A cataract occurs when clouding develops in the eye's crystalline lens. The lens is a critical component of the eye, as it helps to focus light onto the retina at the back of the eye. The lens also adjusts the eye's focus, permitting objects to be seen clearly both close up and far away.
All cells within the body degenerate and regenerate. As we age, however, proteins can build up on the crystalline lens and obstruct or deflect some of the light that should pass through it. Cataracts can occur as different types, including nuclear, cortical, or other forms.
A nuclear cataract is most commonly seen as it forms. This cataract forms in the nucleus, the center of the lens, and is due to the natural aging process. A cortical cataract, which forms in the lens cortex, gradually extends its spokes from the outside of the lens to the center. These often have a star-like shape and appearance. Many diabetics develop cortical cataracts.
A cataract starts out small, and at first has little effect on your vision. You may notice that your vision is blurred a little, like looking through a cloudy piece of glass. The cataract may make light from the sun or a lamp seem too bright, causing glare. With cataracts you may notice when you drive at night that the oncoming headlights cause more glare than before. Colors may not appear as bright as they once did.
Cataracts are easily treated through surgery for extraction of the cataractous lens and implantation of a synthetic replacement lens. In some cases however, surgery is not an option due to complicating health problems or other reasons. Surgery may also be delayed for various reasons. In these cases, Low Vision Aids can be critical in assisting the cataract sufferer maintain visual functioning.