What is a cataract? A cataract is a cloudy or opaque area in the normally transparent lens of the eye. Its effect on vision depends on the extent of the cloudiness. Small spots in the lens may cause little or no vision loss. As the opacity thickens, itprevents light rays from passing through the lens and focusing on the retina, the lightsensitive tissue lining the back of the eye. Early lens changes or opacities may not disturbvision. But as the lens continues to change, several specific symptoms including blurredvision; sensitivity to light and glare; increased nearsightedness; or distorted images ineither eye, may develop. Cataracts are usually associated with aging. As a person growsolder, the lens becomes less flexible and loses some of its ability to focus light onto theretina. As the lens becomes harder, it tends to develop cataracts. Cataracts can eventuallybecome milky white and fill the lens. The patient is then considered blind. Doctors do notknow how to prevent or cure most types of cataracts. But surgery to remove the diseasedlens can improve vision for most cataract patients. After such surgery, some patients. After such surgery, some patients must wear strong glasses or contact lenses to see wellenough to carry on normal activities. In most cases, however, surgeons replace thediseased lens with a plastic intraocular lens. A patient who receives an intraocular lensmay or may not need glasses or contact lenses to see well.Physiology Of A Normal SystemThe eye normally consist of a lens that is located behind the iris, the coloredportion of the eye, and the pupil, the dark center of the eye. Tiny ligaments, calledzonules, support the lens capsule within the eye (American Academy of Ophthalmology,10). The lens has three parts, the capsule, the nucleus, and the cortex. The outermembrane, or capsule, surrounds the cortex which in turn surrounds the center or nucleus of the lens. If you imagine the lens as a p...
