Laser trabeculoplasty as initial glaucoma therapy avoids complications caused by medications and filtration surgery, but can require repeat laser later, a glaucoma specialist said.
Speaking at Hawaiian Eye 2007, L. Jay Katz, MD, said physicians have been performing laser trabeculoplasty for more than 25 years and noted there is still confusion among surgeons about its uses. He said he uses it in a nontraditional role, as initial therapy, in certain patients instead of medications or filtration surgery.
“When you’re looking at laser trabeculoplasty — whether it is [argon laser trabeculoplasty] or [selective trabeculoplasty] — there seems to be a comparable IOP reduction when looking at lasers and medication as initial therapy,” he said. “But clearly, on the safety issues, compliance and cost, I think the laser certainly wins in those categories.”
Dr. Katz said laser as initial therapy will not be right for all patients. Each patient should be treated on a case-by-case basis, and all options should be explored before selecting one. Dr. Katz recommended that doctors offer newly diagnosed glaucoma patients the option of laser trabeculoplasty as a “reasonable” first-line treatment, instead of prescribing medications in a “knee-jerk response.”
Why initial treatment?
Dr. Katz said the standard glaucoma treatment paradigm has typically proceeded in the following order: maximal medical therapy, laser trabeculoplasty and filtering surgery. This paradigm is in transition with National Eye Institute studies, such as the Glaucoma Laser Trial, that have examined the use of ALT at the beginning of the treatment sequence or the more recent studies looking at SLT as initial therapy, he said.
He said the main reason to consider laser trabeculoplasty as initial treatment is because of the many complications posed by glaucoma medications and filtration surgery. Medications, although effective in many ways, also have ocular and systemic side effects, Dr. Katz said. Drug therapy may pose compliance issues with patients who do not take their medications for various reasons, including cost. Some patients may be nonresponsive to available medications. Tachyphylaxis, or long-term loss of efficacy, and peak/trough issues, concerning the variability of maintaining IOP over extended periods of time, are additional problems, Dr. Katz said.
“Finally, we have new concerns with some of the glaucoma medications that are coming to the forefront,” Dr. Katz said. “Maybe they’re cataractogenic – there’s been accelerated cataract development noted in trials comparing medical therapy with observation. [Benzalkonium chloride] surface toxicity on the conjunctiva may impair later filtration surgery, and there are some theoretical concerns that certain drugs may be impairing the circulation to the retina and the optic nerve.”
Filtering surgery can be associated with a number of intraoperative and postoperative complications and requires lengthy rehabilitation, Dr. Katz said.
In contrast, the main complication of laser trabeculoplasty is an IOP spike, he said. The IOP spike is usually transient, but is sometimes sustained, Dr. Katz said. The risk can be reduced with fewer shots, less energy and the use of alpha agonists in the perilaser period. Patients are at increased risk of spikes if they are on multiple medications, the procedure is a re-treatment, there is heavy trabecular meshwork pigmentation (eg pigmentary glaucoma) and the surgeon uses 360° treatment at one sitting instead of 180°, he said.
Study results
Many studies have been conducted looking at the repeatability and initial treatment possibilities of laser trabeculoplasty procedures, Dr. Katz said. One study, which was presented at the Association for Research and Vision in Ophthalmology meeting in 2005, examined 30 eyes. It found that by repeating the SLT as initial treatment 1 year after the first treatment, 80% of the time, there was a reasonable response with lowered IOP, he said.
Another study presented at ARVO in 2005 looked at patients who were treated with SLT, with at least 1-year follow-up. More than half of the eyes in the study, or 54%, had a successful response. About half, or 48%, of patients with repeat SLT had a good response, Dr. Katz said.
There have been a number of studies performed outside of the United States that examined SLT as primary therapy, Dr. Katz said. “Uniformly, the nonrandomized studies have shown that SLT seems to lower pressure fairly well as a standalone procedure,” he said.
A prospective study by Shlomo Melamed, MD, and colleagues in Israel looked at 45 eyes of 31 patients who underwent SLT. Forty eyes had more than a 5-mm Hg drop in IOP with SLT, with an initial IOP of 25.5 mm Hg.
A nonrandomized prospective study in Canada looked at primary SLT as compared with a control group of latanoprost as initial therapy, Dr. Katz said. It showed there was a comparable drop between SLT and latanoprost. In the 74 eyes that had SLT, there was a drop in IOP of 8.3 mm Hg, or 31%. In the 26 eyes with latanoprost, the IOP drop was 7.7 mm Hg (31%).
The SLT/Medications Trial, a prospective study that randomly assigned patients but not eyes in the United States and Canada, took place at 17 sites, Dr. Katz said. The study compared SLT with topical medical therapy as initial therapy. Initial results show that patients had comparable baseline IOP reduction rates after at least 8 months of follow-up. Mesan IOP reduction in the medication group was 7.2 mm Hg, and in the SLT group it was 6.7 mm Hg, Dr. Katz said.
The long term benefit of SLT and the efficacy of repeat treatments remain unclear, but it remains a reasonable option for certain patients as initial therapy.
For more information, visit http://www.eyevisionimprovement.com/
source:
http://www.osnsupersite.com/view.aspx?rid=21154
Wednesday, February 24, 2010
Tuesday, February 23, 2010
Eye Fatigue Symptoms
It is believed that up to 90% of computer users develop a condition called Computer Vision Syndrome after 2 hours of computer use which is caused by eye muscle fatigue. And 70 to 75% of those computer users will need computer glasses to relieve their eye fatigue symptoms.
Some of the major eye fatigue symptoms related to Computer Vision Syndrome (CVS) are:
Tired and burning eyes from constant focusing on a computer that is too close to the eyes. The computer screen should be no closer than 20 to 26 inches from the eyes. The further the computer screen is from the eyes the less eye strain that develops, and the longer you can use the computer without symptoms.
Eye strain can develop from eye muscle fatigue, and if left uncorrected, this eye fatigue could cause intraocular muscle spasm resulting in pseudo-myopia. This is a form of transient nearsightedness that causes the distance vision to blur when looking up after prolong computer use. Computer glasses are designed to correct this problem. Sometimes glasses with a weak base-in prism or ultra-violet coatings give some relief as well. The former bolsters up weak converging eye muscles, and the latter tends to block out some of the blue wave length from the harsh white light of fluorescent tubes.
Eye squinting to overcome blurred vision can ultimately cause headaches, increased astigmatism and wrinkles at the corner of the eyes called 'crows feet'.
Glare contributes to eyestrain and can be diminished wth glare screen filters and anti-reflective eyeglass coatings on the glasses. Decreasing the ambient light in the room by 1/2, and redirect it so that it doesn't reflect off the computer screen also helps. Indirect light causes less glare than direct light. Glasses with light gray or pink tints may help as well as anti-reflective coatings. Up to 30% of visual symptoms are caused in some degree from improper lighting.
Dry eyes can result if you stare at the computer screen to long, causing a drop in the blink rate to about 1/5 the normal rate. This can be relieved if you stop every 20 minutes and look at someting 20 feet away for 20 seconds. A dry climate and indoor air conditioned which produces dry air also contibutes to dry eyes. Blinking more and using artificial tears and eye lubricants should help.
Sore neck, back and shoulder muscles can result from poor posture and not taking enough breaks as well as using a bifocal when at the computer. Since the reading portion is at the bottom of the lens it requires the tilting back of the head to see the computer thru the reading portion. This becomes very uncomfortable in just a few minutes.
Computer glasses and reading eyeglasses are designed to reduce these eye fatigue symptoms.
For more information, visit http://www.eyevisionimprovement.com/
source:
http://www.computervisionreadingeyeglasses.com/eye_fatigue_symptoms.htm
Some of the major eye fatigue symptoms related to Computer Vision Syndrome (CVS) are:
Tired and burning eyes from constant focusing on a computer that is too close to the eyes. The computer screen should be no closer than 20 to 26 inches from the eyes. The further the computer screen is from the eyes the less eye strain that develops, and the longer you can use the computer without symptoms.
Eye strain can develop from eye muscle fatigue, and if left uncorrected, this eye fatigue could cause intraocular muscle spasm resulting in pseudo-myopia. This is a form of transient nearsightedness that causes the distance vision to blur when looking up after prolong computer use. Computer glasses are designed to correct this problem. Sometimes glasses with a weak base-in prism or ultra-violet coatings give some relief as well. The former bolsters up weak converging eye muscles, and the latter tends to block out some of the blue wave length from the harsh white light of fluorescent tubes.
Eye squinting to overcome blurred vision can ultimately cause headaches, increased astigmatism and wrinkles at the corner of the eyes called 'crows feet'.
Glare contributes to eyestrain and can be diminished wth glare screen filters and anti-reflective eyeglass coatings on the glasses. Decreasing the ambient light in the room by 1/2, and redirect it so that it doesn't reflect off the computer screen also helps. Indirect light causes less glare than direct light. Glasses with light gray or pink tints may help as well as anti-reflective coatings. Up to 30% of visual symptoms are caused in some degree from improper lighting.
Dry eyes can result if you stare at the computer screen to long, causing a drop in the blink rate to about 1/5 the normal rate. This can be relieved if you stop every 20 minutes and look at someting 20 feet away for 20 seconds. A dry climate and indoor air conditioned which produces dry air also contibutes to dry eyes. Blinking more and using artificial tears and eye lubricants should help.
Sore neck, back and shoulder muscles can result from poor posture and not taking enough breaks as well as using a bifocal when at the computer. Since the reading portion is at the bottom of the lens it requires the tilting back of the head to see the computer thru the reading portion. This becomes very uncomfortable in just a few minutes.
Computer glasses and reading eyeglasses are designed to reduce these eye fatigue symptoms.
For more information, visit http://www.eyevisionimprovement.com/
source:
http://www.computervisionreadingeyeglasses.com/eye_fatigue_symptoms.htm
Astigmatism Correction
IntroductionAuthor: Sherman Winston Reeves, M.D., M.P.H.
Astigmatism is a common condition where light entering the eye gets bent or focused unequally in one meridian versus another. A common analogy is a spoon (or football) with its curvatures varying, being less curved, or flatter, along the length of the spoon and more curved along the width of the spoon. A person with astigmatism sees a smear or shadow image coming off the object viewed. It can coexist with nearsightedness or farsightedness, and will cause things to appear blurry at distance and near. Uncorrected astigmatism may also cause eyestrain and headaches. Fortunately, it is usually easily corrected by glasses or contact lenses. Contact lenses that correct astigmatism fall into two main types: rigid gas permeable and soft. Both vary considerably in their advantages and disadvantages which will be detailed in this article.
What is astigmatism?
Astigmatism is a type of refractive error where light rays focus at different points in the eye. This creates a blurry image affecting both the distance and near acuity. Astigmatism can be caused by the shape or curvature of the cornea being more football- shaped versus round in a spherical eye or by the lens inside of the eye. There are two types of astigmatism: regular and irregular. Regular astigmatism, which affects the majority of people, occurs when part of the eye which needs the most amount of power exists 90 degrees away from the area in the eye needing the least amount of power. It is symmetrical, and because of this regularity, it is easily corrected with glasses or contacts. In irregular astigmatism, the cornea, which is the front curve of the eye, may not be smooth or it may be asymmetric. This causes light to be scattered throughout the eye with many different focus points. Neither glasses nor soft contacts can correct this condition and because of this, rigid gas permeable lenses are often a medical necessity to provide the bearer with crisp vision.
What causes astigmatism?
Astigmatism is not a disease. It often occurs naturally with some likelihood of a familial inheritance. It can change naturally over a person’s lifetime. Sometimes, astigmatism can be a symptom of eye diseases such as keratoconus or cataracts. It also can be a result of various ocular surgeries or injuries.
How is astigmatism detected?
Astigmatism is easily quantified by two common tests during an eye exam. The first is keratometry, a quick test measuring the two main corneal curvatures of the cornea. Your eye doctor may do this as part of a routine eye exam. It is especially important if you are being fit with contact lenses. The second is the refraction. This is the part of the exam in which you choose between a variety of views or lenses to determine your prescription for glasses and eventually contact lenses. Not as commonly used is topography, which is a mapping of the cornea that shows the astigmatism with even greater detail and may be done if you are considering surgery or if there is suspicion of irregular astigmatism.
What types of contacts for astigmatism correction?
Gas Permeable (GP)
A GP lens is a semi-hard lens which is often smaller than a soft contact lens. It corrects for astigmatism by acting to make the surface of the eye spherical. It does this by usually being spherical itself; one’s tears fill the space between the lens and the spoon-shaped cornea. If a high amount of astigmatism is coming from the natural lens in the eye versus the cornea, this spherical design doesn’t work as well, and your doctor may prescribe a more sophisticated lens such as a front-toric or bitoric design. If your eye has a lot of astigmatism, he or she may fit you with a back-toric design or other specialty lens to get a more comfortable fit.
The advantages of GPs include clear, stable astigmatic correction, and they also can be more economical over a person’s wearing lifetime. That is, the same pair of lenses may last a person several years, even though the initial cost can sometimes be a bit more than a soft lens. They are durable and not as likely to tear or develop deposits as a soft lens. They are also easy to handle and get in and out of the eye. Some are available in special materials that permit up to thirty days of continuous wear. There is even some data suggesting that GPs can slow down the progression of nearsightedness in childrens’ developing eyes.
GPs are the primary way to correct for irregular astigmatism, which may be the result of diseases like keratoconus or seen after a cornea transplant or other surgery. Again the tears fill the space between the lens and the irregular cornea making for a smoother optical surface and crisper vision.
The biggest disadvantage of a GP lens is its initial comfort. As you can imagine, a rigid piece of plastic in the eye takes more getting used to than a soft. It can take a couple of weeks of consistent wear to become accustomed to how this lens feels in the eye. A small number of patients never find them comfortable. Most patients adapt and can wear the lenses all their waking hours comfortably.
What About Correcting Astigmatism with Soft Toric Contact Lenses?
A soft toric contact lens is a hydrophilic, flexible material lens, which has different powers in opposing meridians built into the lens. In order to correct for the astigmatism appropriately, the powers have to align with the right areas of the eye. There are various designs to allow for this, but a common one is prism ballast, where there is a thicker spot on the soft lens, which naturally rests on the bottom of the lens to help hold the lens in position. Without that, or another stabilization method, the vision would be highly variable. As the patient blinks the contact lens could endlessly rotate.
The advantages of a soft toric contact lens include easy adaptability; the comfort is usually quite good even initially. They come in an extended wear option, allowing up to thirty days of continuous (overnight) wear. They can come in colors, which can change even the darkest eyes to a variety of colors. Soft toric contacts are available in a variety of replacement schedules. There are conventional lens designs, in which you keep the same lenses for a year, and more commonly those called ‘disposable lenses’ which you wear for one month, 2 weeks, or only once and throw away, with no need to ever clean them. Perhaps the most popular is a two to four week disposable contact lens.
Prices vary quite a bit depending on the brand and replacement schedule, but they are often less expensive than a pair of eyeglasses. With disposable lenses, it is much easier to change the powers, which is convenient for a person with an unstable prescription. Disposables, when replaced regularly, are also healthier for the eyes compared to yearly replacement lenses because they are less likely to have dirt and deposits that attract bacteria and can cause infections. Handling and cleaning soft contacts is usually quite simple as well.
Their biggest drawback is the potential for fluctuating vision. No matter how good the lens design and fit, all soft toric lenses rotate and move somewhat in the eye, and as explained earlier, this can be a source of frustration when you can see clearly one minute, and are blurry the next. The more astigmatism a person has, the more sensitive he/she is likely to be to lens movement. A way to test if this may be an issue for you is to take your glasses and rotate them in front of your eyes. If a little movement creates a big blur, you may be better off, vision-wise, with an RGP instead.
What Other Contact Lens Options Exist for Correction of Astigmatism?
Beyond GP and soft toric contact lenses, there are now hybrid lenses, which either have a soft lens surround (or skirt) with a rigid central portion or the lens, or are made of a stiffer soft lens material. Lens designs such as these try to combine the benefits that each lens has to offer and may be best for a difficult to fit eye, like one with irregular astigmatism.
Another type of contact lens, which really is a type of GP, is called Corneal Refractive Therapy (CRT) or Orthokeratology lenses. This, essentially, is an RGP lens worn while sleeping designed to mold the eye. The fit of the contact is such that it reshapes the cornea by pushing on the steep areas much like an oral retainer does to teeth. The flattening effect of the contact lens typically lasts all day to enable the wearer to see clearly without a lens while awake, but then the user would need to resume wear again the next night to maintain clear vision the following day. It works best for mild to moderate amounts of nearsightedness and less than one and a half diopters of astigmatism.
What Type of Complications Exist with Astigmatism Correcting Contact Lenses?
With any type of contact lens, there is an increased risk of infection. For this reason it is extremely important to be fit by an eye doctor with a proper lens for your particular eye and to follow the appropriate cleaning and wearing directions. In addition to infection, overwearing contacts can lead to hypoxia wherein the normally clear cornea can develop blood vessels from a lack of oxygen. Contacts can also induce warpage of the cornea, which can make it hard to see clearly out of glasses immediately after removing the contacts.
Who cannot wear contacts?
Your eye doctor can tell you if you are an appropriate candidate for contacts. He/she will want to make sure that you don’t have severe dry eye or blepharitis that may interfere with the comfort of contacts. Sensitivity to the lens cleaning solutions may also make contact lens use uncomfortable, but specific solutions are available to address that problem, if necessary.
For more information about natural astigmatism correction, visit http://www.eyevisionimprovement.com/ and get some free tips.
source :
http://www.improveyourvision.com/understanding-vision/problems-diseases/astigmatism.html
Astigmatism is a common condition where light entering the eye gets bent or focused unequally in one meridian versus another. A common analogy is a spoon (or football) with its curvatures varying, being less curved, or flatter, along the length of the spoon and more curved along the width of the spoon. A person with astigmatism sees a smear or shadow image coming off the object viewed. It can coexist with nearsightedness or farsightedness, and will cause things to appear blurry at distance and near. Uncorrected astigmatism may also cause eyestrain and headaches. Fortunately, it is usually easily corrected by glasses or contact lenses. Contact lenses that correct astigmatism fall into two main types: rigid gas permeable and soft. Both vary considerably in their advantages and disadvantages which will be detailed in this article.
What is astigmatism?
Astigmatism is a type of refractive error where light rays focus at different points in the eye. This creates a blurry image affecting both the distance and near acuity. Astigmatism can be caused by the shape or curvature of the cornea being more football- shaped versus round in a spherical eye or by the lens inside of the eye. There are two types of astigmatism: regular and irregular. Regular astigmatism, which affects the majority of people, occurs when part of the eye which needs the most amount of power exists 90 degrees away from the area in the eye needing the least amount of power. It is symmetrical, and because of this regularity, it is easily corrected with glasses or contacts. In irregular astigmatism, the cornea, which is the front curve of the eye, may not be smooth or it may be asymmetric. This causes light to be scattered throughout the eye with many different focus points. Neither glasses nor soft contacts can correct this condition and because of this, rigid gas permeable lenses are often a medical necessity to provide the bearer with crisp vision.
What causes astigmatism?
Astigmatism is not a disease. It often occurs naturally with some likelihood of a familial inheritance. It can change naturally over a person’s lifetime. Sometimes, astigmatism can be a symptom of eye diseases such as keratoconus or cataracts. It also can be a result of various ocular surgeries or injuries.
How is astigmatism detected?
Astigmatism is easily quantified by two common tests during an eye exam. The first is keratometry, a quick test measuring the two main corneal curvatures of the cornea. Your eye doctor may do this as part of a routine eye exam. It is especially important if you are being fit with contact lenses. The second is the refraction. This is the part of the exam in which you choose between a variety of views or lenses to determine your prescription for glasses and eventually contact lenses. Not as commonly used is topography, which is a mapping of the cornea that shows the astigmatism with even greater detail and may be done if you are considering surgery or if there is suspicion of irregular astigmatism.
What types of contacts for astigmatism correction?
Gas Permeable (GP)
A GP lens is a semi-hard lens which is often smaller than a soft contact lens. It corrects for astigmatism by acting to make the surface of the eye spherical. It does this by usually being spherical itself; one’s tears fill the space between the lens and the spoon-shaped cornea. If a high amount of astigmatism is coming from the natural lens in the eye versus the cornea, this spherical design doesn’t work as well, and your doctor may prescribe a more sophisticated lens such as a front-toric or bitoric design. If your eye has a lot of astigmatism, he or she may fit you with a back-toric design or other specialty lens to get a more comfortable fit.
The advantages of GPs include clear, stable astigmatic correction, and they also can be more economical over a person’s wearing lifetime. That is, the same pair of lenses may last a person several years, even though the initial cost can sometimes be a bit more than a soft lens. They are durable and not as likely to tear or develop deposits as a soft lens. They are also easy to handle and get in and out of the eye. Some are available in special materials that permit up to thirty days of continuous wear. There is even some data suggesting that GPs can slow down the progression of nearsightedness in childrens’ developing eyes.
GPs are the primary way to correct for irregular astigmatism, which may be the result of diseases like keratoconus or seen after a cornea transplant or other surgery. Again the tears fill the space between the lens and the irregular cornea making for a smoother optical surface and crisper vision.
The biggest disadvantage of a GP lens is its initial comfort. As you can imagine, a rigid piece of plastic in the eye takes more getting used to than a soft. It can take a couple of weeks of consistent wear to become accustomed to how this lens feels in the eye. A small number of patients never find them comfortable. Most patients adapt and can wear the lenses all their waking hours comfortably.
What About Correcting Astigmatism with Soft Toric Contact Lenses?
A soft toric contact lens is a hydrophilic, flexible material lens, which has different powers in opposing meridians built into the lens. In order to correct for the astigmatism appropriately, the powers have to align with the right areas of the eye. There are various designs to allow for this, but a common one is prism ballast, where there is a thicker spot on the soft lens, which naturally rests on the bottom of the lens to help hold the lens in position. Without that, or another stabilization method, the vision would be highly variable. As the patient blinks the contact lens could endlessly rotate.
The advantages of a soft toric contact lens include easy adaptability; the comfort is usually quite good even initially. They come in an extended wear option, allowing up to thirty days of continuous (overnight) wear. They can come in colors, which can change even the darkest eyes to a variety of colors. Soft toric contacts are available in a variety of replacement schedules. There are conventional lens designs, in which you keep the same lenses for a year, and more commonly those called ‘disposable lenses’ which you wear for one month, 2 weeks, or only once and throw away, with no need to ever clean them. Perhaps the most popular is a two to four week disposable contact lens.
Prices vary quite a bit depending on the brand and replacement schedule, but they are often less expensive than a pair of eyeglasses. With disposable lenses, it is much easier to change the powers, which is convenient for a person with an unstable prescription. Disposables, when replaced regularly, are also healthier for the eyes compared to yearly replacement lenses because they are less likely to have dirt and deposits that attract bacteria and can cause infections. Handling and cleaning soft contacts is usually quite simple as well.
Their biggest drawback is the potential for fluctuating vision. No matter how good the lens design and fit, all soft toric lenses rotate and move somewhat in the eye, and as explained earlier, this can be a source of frustration when you can see clearly one minute, and are blurry the next. The more astigmatism a person has, the more sensitive he/she is likely to be to lens movement. A way to test if this may be an issue for you is to take your glasses and rotate them in front of your eyes. If a little movement creates a big blur, you may be better off, vision-wise, with an RGP instead.
What Other Contact Lens Options Exist for Correction of Astigmatism?
Beyond GP and soft toric contact lenses, there are now hybrid lenses, which either have a soft lens surround (or skirt) with a rigid central portion or the lens, or are made of a stiffer soft lens material. Lens designs such as these try to combine the benefits that each lens has to offer and may be best for a difficult to fit eye, like one with irregular astigmatism.
Another type of contact lens, which really is a type of GP, is called Corneal Refractive Therapy (CRT) or Orthokeratology lenses. This, essentially, is an RGP lens worn while sleeping designed to mold the eye. The fit of the contact is such that it reshapes the cornea by pushing on the steep areas much like an oral retainer does to teeth. The flattening effect of the contact lens typically lasts all day to enable the wearer to see clearly without a lens while awake, but then the user would need to resume wear again the next night to maintain clear vision the following day. It works best for mild to moderate amounts of nearsightedness and less than one and a half diopters of astigmatism.
What Type of Complications Exist with Astigmatism Correcting Contact Lenses?
With any type of contact lens, there is an increased risk of infection. For this reason it is extremely important to be fit by an eye doctor with a proper lens for your particular eye and to follow the appropriate cleaning and wearing directions. In addition to infection, overwearing contacts can lead to hypoxia wherein the normally clear cornea can develop blood vessels from a lack of oxygen. Contacts can also induce warpage of the cornea, which can make it hard to see clearly out of glasses immediately after removing the contacts.
Who cannot wear contacts?
Your eye doctor can tell you if you are an appropriate candidate for contacts. He/she will want to make sure that you don’t have severe dry eye or blepharitis that may interfere with the comfort of contacts. Sensitivity to the lens cleaning solutions may also make contact lens use uncomfortable, but specific solutions are available to address that problem, if necessary.
For more information about natural astigmatism correction, visit http://www.eyevisionimprovement.com/ and get some free tips.
source :
http://www.improveyourvision.com/understanding-vision/problems-diseases/astigmatism.html
Eye Strain Headache
There are several types of headaches, some common and some complex, resulting in many types of treatments; but for those working specificially with computers may experience a computer eye strain headache. An Eye strain headache is a common type of tension headache.
Tension headaches are by far the most common type of headache. Estimates are that from 70 to 90% of all headaches are tension headaches resulting from muscle spasms in the neck and skull. Common causes like eye strain, muscle fatigue, poor posture, overwork, and stress can bring them on. Anything that can help the body to relax can help relieve the pain such as rest, massage, especially to the skull, neck and shoulders, and exercise. We have developed headache relief exercises for the eyes, using a device specifically designed for the relief from a tension headaches that occur when doing near work such as reading and using the computer.
If you still get headaches after using the eye exercises for a few weeks, the cause may be from one of the following:
- Hormonal headaches that revolve around the menstrual cycle. Since homones induce the pain response, mens headaches can be prompted by hormones as well.
- Vascular headaches such as migraines afflict up to 29.5 million people. Women get 3 times as many migraines than men so hormones may be involved here as well. It is probably tension that causes a constriction of the blood vessel in the brain that produces the visual effect or aura. Shortly thereafter it is replaced with a very severe headache as the involved blood vessel overly dilates to provide increase blood flow to the affected area. Some get physically sick from the severe pain, which is why they have been called sick headaches. There is most likely a genetic component since 4 out of 5 afflicted report family members also get them.
- Cluster headaches have been described as the most painful of all headaches. They last around 1/2 hour but may reoccur multiple times during the day. Around 5 times as many men as women suffer this type of pain. Fortunately less than 1% of the population get them.
Sinus headaches occur when the sinuses get inflammed either from an allergy, an infection or a growth.
- Organic headaches result in less than 5 % of the cases and are caused from an abnormality in the brain or skull such as a tumor, infection, hemorrhage, aneurysm, hematoma, meningitis, brain abcess or encephallitis.
Remember a headache while at the computer is usually a tension type headache so anything that will help the eye muscles to relax should bring significant relief to an eye strain headache.
For more information about how to managae eye strain heaache naturally, visit http://www.eyevisionimprovement.com/ and get some free tips.
source :
http://www.computervisionreadingeyeglasses.com/eye_strain_headaches.htm
Tension headaches are by far the most common type of headache. Estimates are that from 70 to 90% of all headaches are tension headaches resulting from muscle spasms in the neck and skull. Common causes like eye strain, muscle fatigue, poor posture, overwork, and stress can bring them on. Anything that can help the body to relax can help relieve the pain such as rest, massage, especially to the skull, neck and shoulders, and exercise. We have developed headache relief exercises for the eyes, using a device specifically designed for the relief from a tension headaches that occur when doing near work such as reading and using the computer.
If you still get headaches after using the eye exercises for a few weeks, the cause may be from one of the following:
- Hormonal headaches that revolve around the menstrual cycle. Since homones induce the pain response, mens headaches can be prompted by hormones as well.
- Vascular headaches such as migraines afflict up to 29.5 million people. Women get 3 times as many migraines than men so hormones may be involved here as well. It is probably tension that causes a constriction of the blood vessel in the brain that produces the visual effect or aura. Shortly thereafter it is replaced with a very severe headache as the involved blood vessel overly dilates to provide increase blood flow to the affected area. Some get physically sick from the severe pain, which is why they have been called sick headaches. There is most likely a genetic component since 4 out of 5 afflicted report family members also get them.
- Cluster headaches have been described as the most painful of all headaches. They last around 1/2 hour but may reoccur multiple times during the day. Around 5 times as many men as women suffer this type of pain. Fortunately less than 1% of the population get them.
Sinus headaches occur when the sinuses get inflammed either from an allergy, an infection or a growth.
- Organic headaches result in less than 5 % of the cases and are caused from an abnormality in the brain or skull such as a tumor, infection, hemorrhage, aneurysm, hematoma, meningitis, brain abcess or encephallitis.
Remember a headache while at the computer is usually a tension type headache so anything that will help the eye muscles to relax should bring significant relief to an eye strain headache.
For more information about how to managae eye strain heaache naturally, visit http://www.eyevisionimprovement.com/ and get some free tips.
source :
http://www.computervisionreadingeyeglasses.com/eye_strain_headaches.htm
Monday, February 22, 2010
Eyesight Correction
There are now numerous methods of eyesight correction available to you today. Even severe eyesight conditions can now be treated. You can have laser eye surgery, or if your eye prescription is outside the limit for LASIK, you could opt to get implantable contact lenses. These eyesight correction methods have about 95% success rate, which is a good news indeed to billions of people suffering with eyesight problems worldwide.
The Laser Eye Treatment
One eyesight correction method that has become extremely popular is the laser eye treatment. The safety of this procedure is measured by the number of success stories resulting from people who had undergone LASIK eyesight correction. There are numerous testimonials made by people on how successful treatments were and how it made so much difference in their lives.
LASIK eyesight correction, however, is not 100% risk free. There are potential side effects and problems that may results although serious complications are rare. Complications, if they occur, are minimal and usually resolve themselves after some time. However, the final outcome of the LASIK eyesight correction is not guaranteed. The results vary from one individual to another. Your neighbor might not be too satisfied with the result of his treatment, but you could be ecstatic about it. The healing process also differs from one person to another.
Overall, laser eyesight correction surgeries are safe. There is an estimated 2 million procedures that are carried out every year worldwide. The procedure is mostly safe and the predictability of the outcome of the eyesight correction treatment is high. This is largely because there are excellent studies and researches on laser surgeries being conducted. There are now hundreds of highly skilled and competent ophthalmologists performing laser eyesight correction surgeries worldwide.
Things to Consider
After surgery and you’re cleared by your ophthalmologist for regular activities, you can then resume doing all forms of activities like sports, driving, et cetera. Contact sports should be avoided though as well as nighttime driving. But as a preventive measure and a part of your eyesight correction treatment, you may be instructed to avoid strong sunlight, dust and dirt exposure. Also, you should avoid swimming for a few weeks until your eyes have recovered.
If the results are good, you can expect that it would be more or less permanent. There is no assurance though that there is no risk of reversibility. Some people’s condition comes back after a few months or years. Overall though, the rate of permanency is higher than reversibility.
source:
http://www.sethson.com/eyesight-correction-with-lasik-and-laser-eye-surgery/
The Laser Eye Treatment
One eyesight correction method that has become extremely popular is the laser eye treatment. The safety of this procedure is measured by the number of success stories resulting from people who had undergone LASIK eyesight correction. There are numerous testimonials made by people on how successful treatments were and how it made so much difference in their lives.
LASIK eyesight correction, however, is not 100% risk free. There are potential side effects and problems that may results although serious complications are rare. Complications, if they occur, are minimal and usually resolve themselves after some time. However, the final outcome of the LASIK eyesight correction is not guaranteed. The results vary from one individual to another. Your neighbor might not be too satisfied with the result of his treatment, but you could be ecstatic about it. The healing process also differs from one person to another.
Overall, laser eyesight correction surgeries are safe. There is an estimated 2 million procedures that are carried out every year worldwide. The procedure is mostly safe and the predictability of the outcome of the eyesight correction treatment is high. This is largely because there are excellent studies and researches on laser surgeries being conducted. There are now hundreds of highly skilled and competent ophthalmologists performing laser eyesight correction surgeries worldwide.
Things to Consider
After surgery and you’re cleared by your ophthalmologist for regular activities, you can then resume doing all forms of activities like sports, driving, et cetera. Contact sports should be avoided though as well as nighttime driving. But as a preventive measure and a part of your eyesight correction treatment, you may be instructed to avoid strong sunlight, dust and dirt exposure. Also, you should avoid swimming for a few weeks until your eyes have recovered.
If the results are good, you can expect that it would be more or less permanent. There is no assurance though that there is no risk of reversibility. Some people’s condition comes back after a few months or years. Overall though, the rate of permanency is higher than reversibility.
source:
http://www.sethson.com/eyesight-correction-with-lasik-and-laser-eye-surgery/
Saturday, February 20, 2010
Eyesight Improvement
Eyesight improvement is achievable. You can learn to see without glasses and be relieved permanently of the pain and distress so frequently associated with defective sight. But you cannot do it by magic.
CENTRAL FIXATION
The retina is a sensitive film on which the picture falls. But there is one point on the retina where the vision is perfect; that is the Macula Lutae, a point only one-sixteenth of an inch in diameter in the very center of the retina. When we focus at this point we have what is known as central fixation and our vision is perfect.
If you have lost the capacity of central fixation you are seeing with Eccentric fixation which often causes headaches, fatigue, pain or discomfort of some kind, such as twitching of the eyelids or the eyeballs. This twitching, by the way, can be stopped by pressing the sides of the base of the nose as high as the inner canthus with the forefingers of both hands, avoiding any pressure on the eyeballs. Continue the pressure for several minutes, with the eyes closed, and you will obtain relief.
One way of checking on whether you are seeing by central or eccentric fixation is to look at a word on this page. Do you see it most sharply where you are looking or do you see it better when you look a little away from it? When you look at the top of a printed letter do you see the bottom of the letter more clearly than the top? If so, you have lost central fixation.
If you are to see, you must bring your mind to bear on what you see. Because the eye can focus sharply and is at its maximum power only on a very small area at a time, an attempt to see a larger area results in a blurring of physical vision and a lack of mental focus. Teach yourself to look at what you see, to watch one tiny area at a time. For when the central fixation is perfect, the eye sees perfectly.
THINK ABOUT WHAT YOU SEE
For significant eyesight improvement, give the object you are looking at your mental as well as your visual attention. The more clearly it registers on your mind, the more clearly it will register on the eye.
Test this out for yourself. In the room where you are sitting there are probably a dozen objects which you no longer "see" because you are so accustomed to their presence that you are no longer aware of them. Look at each one in turn, not staring, but with quick, easy glances, thinking about what you are regarding. That doorknob-could you have described it before? Now you know its approximate size, contour, the material of which it is made, its relative position on the door, because your mind and not alone your eyes observed it.
Even such a familiar phenomenon as a moving picture gives us what we believe we see rather than what we actually see. A series of still pictures provides us with an illusion of movement.
SEE A SMALL AREA AT A TIME
Instead of staring, trying to take in a whole picture at one time and thus defeating the object of central fixation, look at one small part of the picture, shift your gaze to another small part, and another, blinking naturally all the time. The smaller the area, the more clearly you will see it.
People who have acquired bad seeing habits always try to increase their area of vision by staring, which defeats its own purpose. Staring not only causes muscular tension but a lowering of vision. You can test this for yourself by staring fixedly at an object or a word on this page. After a few moments of this effort the letters lose their sharp clarity and become blurred.
Eyesight improvement can be achieved with consistent time and effort!
source:
Friday, February 19, 2010
Better Eyesight Without Glasses
In 1977 I decided to try contact lens for the first time. Pre-disposable lens and soft lens, I chose the new thinner flex-lens kind. They were a pain to get accustomed to, but I finally got the trick of putting them in, taking them out, and cleaning them. The only mishap I had with them was when my maid, Ernestine, dusted one of them away that I had placed on my dresser for a few minutes while I took a shower. Bless her heart, she never dusted again after that. But I digress, which is easy to do when I'm writing a review of a book I read so long ago. What I plan to do is to share my memories of the events surrounding my reading of Dr. Bates's book and my attempts to see without corrective lens of any kind.
About the same time I had started the flex-lens, I came across this book on seeing without glasses. I read it assiduously, ready to believe it was possible and to do all the exercises. I spent time palming my eyes (covering them with the palms of my hands to rest them, doing the eye rotation exercises, and testing my eyes daily with a wall eyechart. Not much happened, but I continued anyway.
Then one memorable day, my eyes cleared up - I could see clearly without glasses! Signs along the highway were readable, my contact lens were left in the drawer back home and I could see. There was a little refraction around the edges of objects, but not enough to bother me. I felt wonderful. The next day the wonderful feeling was gone because my eyesight had returned to its normal myopic state and I needed glasses or flex-lens again. What was wrong? I re-doubled my efforts at Bates' exercises and began looking around for other explanations. I found a discouraging one, but one that fitted all the facts as I experienced them: my eyes had begun to accommodate themselves to the shape of the flex-lens and retained that shape for a time after I took them off. I got one or two days like that again later while I was still wearing the flex-lens, but no longer sustained periods of good, uncorrected eyesight.
Soon I switched to the very first soft lens contacts and they were a miserable failure as well. Yes, they corrected my eyesight and were comfortable, but they were also very expensive, and required replacement regularly. Plus there was one major drawback that no one hears about: wind blowing hard against one's face while wearing contacts is very uncomfortable. Seems the soft ones were slightly better for me while riding a motorcycle, but since I was using my motorcycle and convertible MG TD a lot, the contacts finally had to go since I was mostly wearing eyeglasses again.
Since that time, I have refused to attempt any contact lens or other corrections of my eyesight. I wear Zeiss unifocal lens as the lightest and best vision (and most expensive) lens I could find and I am very happy every time I put on my glasses to have the correction and convenience of lens that I can take on and off at my ease, that don't pop out of my eyes and disappear, and that allow me to see comfortably and feel at ease in a strong breeze.
This is only my own case history of using what is called the Bates Method for "Better Eyesight Without Glasses." Since my adventures in achieving what the title suggests is possible, several new technologies have come and some have gone. Lasik surgery is the newest procedure, replacing the earlier RK surgical procedure that didn't last long enough for me to learn to spell it. With Lasik, a computer guides a laser beam to reshape the eye's seeing surface. The claims for success match those of the previous panaceas like contact lens, flex-lens, soft lens, disposable lens, RK surgery, and the current fad of Lasik.
I have paid my dues back in the late 70s and early 80s. I spent a lot of money to see without glasses and came back to my old friends after the new ones were so expensive and inconvenient. As my eyeballs change shape with age, I can trust that I will be able to see clearly without having any foreign object touching my eyeballs, not even a laser beam. I can see clearly near and far, sometimes I have to remove my glasses to see very small objects up close, but I will never have to use reading glasses to read because I had my eyes corrected by laser surgery to see clearly at a distance. All those having Lasik surgery now are at the beginning of a stage I went through twenty years ago. I'll check with them in twenty years and see how happy they are with their adventures in "better eyesight without glasses."
source:
http://www.doyletics.com/art/bewgart.htm
About the same time I had started the flex-lens, I came across this book on seeing without glasses. I read it assiduously, ready to believe it was possible and to do all the exercises. I spent time palming my eyes (covering them with the palms of my hands to rest them, doing the eye rotation exercises, and testing my eyes daily with a wall eyechart. Not much happened, but I continued anyway.
Then one memorable day, my eyes cleared up - I could see clearly without glasses! Signs along the highway were readable, my contact lens were left in the drawer back home and I could see. There was a little refraction around the edges of objects, but not enough to bother me. I felt wonderful. The next day the wonderful feeling was gone because my eyesight had returned to its normal myopic state and I needed glasses or flex-lens again. What was wrong? I re-doubled my efforts at Bates' exercises and began looking around for other explanations. I found a discouraging one, but one that fitted all the facts as I experienced them: my eyes had begun to accommodate themselves to the shape of the flex-lens and retained that shape for a time after I took them off. I got one or two days like that again later while I was still wearing the flex-lens, but no longer sustained periods of good, uncorrected eyesight.
Soon I switched to the very first soft lens contacts and they were a miserable failure as well. Yes, they corrected my eyesight and were comfortable, but they were also very expensive, and required replacement regularly. Plus there was one major drawback that no one hears about: wind blowing hard against one's face while wearing contacts is very uncomfortable. Seems the soft ones were slightly better for me while riding a motorcycle, but since I was using my motorcycle and convertible MG TD a lot, the contacts finally had to go since I was mostly wearing eyeglasses again.
Since that time, I have refused to attempt any contact lens or other corrections of my eyesight. I wear Zeiss unifocal lens as the lightest and best vision (and most expensive) lens I could find and I am very happy every time I put on my glasses to have the correction and convenience of lens that I can take on and off at my ease, that don't pop out of my eyes and disappear, and that allow me to see comfortably and feel at ease in a strong breeze.
This is only my own case history of using what is called the Bates Method for "Better Eyesight Without Glasses." Since my adventures in achieving what the title suggests is possible, several new technologies have come and some have gone. Lasik surgery is the newest procedure, replacing the earlier RK surgical procedure that didn't last long enough for me to learn to spell it. With Lasik, a computer guides a laser beam to reshape the eye's seeing surface. The claims for success match those of the previous panaceas like contact lens, flex-lens, soft lens, disposable lens, RK surgery, and the current fad of Lasik.
I have paid my dues back in the late 70s and early 80s. I spent a lot of money to see without glasses and came back to my old friends after the new ones were so expensive and inconvenient. As my eyeballs change shape with age, I can trust that I will be able to see clearly without having any foreign object touching my eyeballs, not even a laser beam. I can see clearly near and far, sometimes I have to remove my glasses to see very small objects up close, but I will never have to use reading glasses to read because I had my eyes corrected by laser surgery to see clearly at a distance. All those having Lasik surgery now are at the beginning of a stage I went through twenty years ago. I'll check with them in twenty years and see how happy they are with their adventures in "better eyesight without glasses."
source:
http://www.doyletics.com/art/bewgart.htm
Wednesday, February 17, 2010
How to Use Vitamins for Healthy Eyesight
It's easy to take good vision for granted; however, if we do not make the effort to maintain our eyesight, we may begin to notice subtle blurring when we try to focus on objects or pictures in a magazine. Fortunately, eyesight is easy to improve using eyesight vitamins and making dietary changes.
Step 1
Consume adequate amounts of antioxidant vitamins A, C and E. These vitamins work best together, so take them at the same time, preferably in the morning after breakfast.
Step 2
Eat liver, whole milk and egg yolk, which contain high amounts of vitamin A. Carrots, sweet potatoes and squash contain carotenoids, which the body converts to vitamin A under optimal conditions. Lutein, lycopene and zeaxanthin are some other eyesight-boosting nutrients found in eggs, fruits and vegetables.
Step 3
Include fatty fish like salmon in your diet or take a good fish oil supplement with adequate DHA and EPA. These essential fatty acids help protect the myelin sheath around the nerves in your eyes.
Step 4
Replace junk-y "white foods" such as processed sugar and wheat with healthy alternatives. Ease into changes by slowly replacing them with whole grains and unprocessed sweeteners, such as rapadura sugar. Your body and eyes will reward you with increased vitality.
Step 5
Eliminate dietary trans-fats such as margarine and partially-hydrogenated vegetable oils. Some studies indicate that consumption of margarine may lead to eye problems such as macular degeneration.
source :
http://www.ehow.com/how_2190839_use-vitamins-healthy-eyesight.html
Step 1
Consume adequate amounts of antioxidant vitamins A, C and E. These vitamins work best together, so take them at the same time, preferably in the morning after breakfast.
Step 2
Eat liver, whole milk and egg yolk, which contain high amounts of vitamin A. Carrots, sweet potatoes and squash contain carotenoids, which the body converts to vitamin A under optimal conditions. Lutein, lycopene and zeaxanthin are some other eyesight-boosting nutrients found in eggs, fruits and vegetables.
Step 3
Include fatty fish like salmon in your diet or take a good fish oil supplement with adequate DHA and EPA. These essential fatty acids help protect the myelin sheath around the nerves in your eyes.
Step 4
Replace junk-y "white foods" such as processed sugar and wheat with healthy alternatives. Ease into changes by slowly replacing them with whole grains and unprocessed sweeteners, such as rapadura sugar. Your body and eyes will reward you with increased vitality.
Step 5
Eliminate dietary trans-fats such as margarine and partially-hydrogenated vegetable oils. Some studies indicate that consumption of margarine may lead to eye problems such as macular degeneration.
source :
http://www.ehow.com/how_2190839_use-vitamins-healthy-eyesight.html
Eyesight Problems
Short-sightedness (myopia)
Short sight occurs when light is focused in front of the retina causing distance vision to become blurred. Near vision, however, is usually clear. Short sight normally develops in childhood or adolescence and is often first noticed at school. Glasses may need to be worn all the time or just for driving, watching TV or sports. Long-sightedness (hypermetropia)Long sight occurs when light is focused behind the retina rather than on it, and the eye has to make a compensating effort to re-focus. This can cause discomfort, headaches or problems with near vision. Glasses may need to be worn all the time or just for close work, such as reading, writing or computer use. In older people, as re-focusing becomes more difficult, distance vision may also become blurred.
Astigmatism
Astigmatism occurs when the curvature of the cornea or lens is not perfectly round. It is sometimes described as the eye being shaped like a rugby ball rather than a football. Most people have a small amount of astigmatism, which may not need correcting. If vision is blurred or headaches occur, your optometrist may recommend glasses are worn all the time or just for specific tasks.
Presbyopia
Presbyopia is the loss of focusing ability that occurs naturally with age. In younger people, the lens is very flexible and the eye has a wide range of focus from far distance to close up. As you get older, the lens slowly loses its flexibility leading to a gradual decline in ability to focus on near objects. Presbyopia is not a disease but a normal and expected change which sooner or later affects everyone, whether you already wear glasses or contact lenses or not. Around the age of 40-45, you will begin to notice that you are holding the newspaper further away or need more light to read small print. There is no advantage in delaying using reading glasses, or changing to bifocals or varifocals. They will not make the eyes lazy. Your optometrist will advise you on the best form of vision correction to suit your individual lifestyle and occupation.
Regular examinations are important throughout life, whether or not you are experiencing problems with your eyesight. Your optometrist will not only test your vision and, if necessary, prescribe glasses or contact lenses, but will also check closely for any early signs of eye disease or other medical condition.
source:
http://www.college-optometrists.org/index.aspx/pcms/site.Public_Related_Links.Eyesight_Problems.Eyesight_Problems_home/
Short sight occurs when light is focused in front of the retina causing distance vision to become blurred. Near vision, however, is usually clear. Short sight normally develops in childhood or adolescence and is often first noticed at school. Glasses may need to be worn all the time or just for driving, watching TV or sports. Long-sightedness (hypermetropia)Long sight occurs when light is focused behind the retina rather than on it, and the eye has to make a compensating effort to re-focus. This can cause discomfort, headaches or problems with near vision. Glasses may need to be worn all the time or just for close work, such as reading, writing or computer use. In older people, as re-focusing becomes more difficult, distance vision may also become blurred.
Astigmatism
Astigmatism occurs when the curvature of the cornea or lens is not perfectly round. It is sometimes described as the eye being shaped like a rugby ball rather than a football. Most people have a small amount of astigmatism, which may not need correcting. If vision is blurred or headaches occur, your optometrist may recommend glasses are worn all the time or just for specific tasks.
Presbyopia
Presbyopia is the loss of focusing ability that occurs naturally with age. In younger people, the lens is very flexible and the eye has a wide range of focus from far distance to close up. As you get older, the lens slowly loses its flexibility leading to a gradual decline in ability to focus on near objects. Presbyopia is not a disease but a normal and expected change which sooner or later affects everyone, whether you already wear glasses or contact lenses or not. Around the age of 40-45, you will begin to notice that you are holding the newspaper further away or need more light to read small print. There is no advantage in delaying using reading glasses, or changing to bifocals or varifocals. They will not make the eyes lazy. Your optometrist will advise you on the best form of vision correction to suit your individual lifestyle and occupation.
Regular examinations are important throughout life, whether or not you are experiencing problems with your eyesight. Your optometrist will not only test your vision and, if necessary, prescribe glasses or contact lenses, but will also check closely for any early signs of eye disease or other medical condition.
source:
http://www.college-optometrists.org/index.aspx/pcms/site.Public_Related_Links.Eyesight_Problems.Eyesight_Problems_home/
Subscribe to:
Posts (Atom)
