Visual DefectsWhat does 20/20 Vision mean?Visual acuity is expressed as a fraction. The top number refers to the distance you stand from the chart. This is usually 20 feet. The bottom number indicates the distance at which a person with normal eyesight could correctly read the line with the smallest letters. Normal vision is considered 20/20. If your vision is 20/40, the line you correctly read at 20 feet could be read by a person with normal vision at 40 feet. Of course, just because 20/20 vision is normal doesn't mean it's perfect. A small percentage of the population is blessed with vision better than 20/20, and just recently researchers unveiled corrective lens that offered vision clo ...view middle of the document...
In other patients poor blood supply to the vital optic nerve fibres, a weakness in the structure of the nerve, and/or a problem in the health of the nerve fibres themselves may cause the damage.Effects of GlaucomaChronic (primary open-angle) glaucoma is the commonest type, and dangerously it has no symptoms until eyesight is lost at a later stage. Damage progresses very slowly and destroys vision gradually, starting with the side vision. One eye covers for the other, and the person remains unaware of any problem until a majority of nerve fibres have been destroyed, and a large part of vision has been destroyed. This damage is irreversible by any means and it's is progression is usually relentless. Treatment cannot recover what has been lost. But it can arrest, or at least, slow down the damage process.Normal Vision The same scene as itmight be viewed by aperson with glaucomaTreatments for GlaucomaAlthough there is no cure for glaucoma it can usually be controlled and further loss of sight either prevented or at least slowed down. Treatment can save remaining vision but it does not improve eyesight.Treatments include:Eye drops - these are the most common form of treatment and must be used regularly. In some cases pills are prescribed. The drops can be varied to best suit the patient and the type of glaucoma.Laser (laser trabeculoplasty) - this is performed when eye drops do not stop deterioration in the field of vision.Conventional Surgery - this is performed usually after eye drops and laser have failed to control the eye pressure...
