A cataract is a clouding of the normally clear lens of the eye. A cataract decreases the amount of light that is focused on the retina, resulting in an overall blurriness of images. Having a cataract disturbs vision much like looking through a fogged windshield.
The lens is the part of the eye that helps focus light on the retina. The retina is the eye's light-sensitive layer that sends visual signals to the brain. In a normal eye, light passes through the lens and gets focused on the retina. To help produce a sharp image, the lens must remain clear.
The lens is made up of mostly water and protein. The protein is arranged to let light pass through and focus on the retina. Sometimes some of the protein clumps together. This can start to cloud small areas of the lens, blocking some light from reaching the retina and interfering with vision.
A cataract can occur in any part of the lens: In the front, center, or the back part. The front cataract causes problem in vision as well as causes glare from the light. Central cataract causes problem in far vision and may not affect reading. Posterior cataract causes problem in reading. A combination of all the 3 forms may also occur.
Saturday, July 28, 2007
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