Cataracts

A cataract is the clouding of the eye's natural lens, which lies behind the iris and the pupil.Cataracts are the most common cause of vision loss in people over age 40 and is the principal cause of blindness in the world. it almost appears a a white spot in place on the black pupil.

Thre are various types of cataracts;
  
1.A subcapsular cataract occurs at the back of the lens. People with diabetes, high farsightedness or retinitis pigmentosa, or
those taking high doses of steroid medications have a greater risk of developing a subcapsular cataract.
  
2.A nuclear cataract forms deep in the central zone (nucleus) of the lens. Nuclear cataracts usually are associated with aging.
  
3.A cortical cataract is characterized by white, wedge-like opacities that start in the periphery of the lens and work their way
to the center in a spoke-like fashion. This type of cataract occurs in the lens cortex, which is the part of the lens that surrounds the central nucleus.

According to webMD "The eye functions much like a camera. Light rays enter the eye, passing through the cornea, the aqueous humor -- transparent fluid in the front of the eye -- and then the pupil and into the lens.The lens bends the light rays to focus objects onto the retina lining the back of the eye. From there, the image passes through the retinal cells, into the optic nerve, and finally to the back of the brain which process the images.Cataracts occur when there is a buildup of protein in the lens that makes it cloudy. This prevents light from passing clearly through a the lens, causing some loss of vision. Since new lens cells form on the outside of the lens, all the older cells are compacted into the center of the lens resulting in the cataract."

Most common cataract symptoms include:

• blurring vision
• sensitivity to light or glare
• double vision in one eye
• poor night vision
• needing brighter light to read
• experiencing fading or yellowing of colors

Treatment being surgery