Blindness

Blindness

Opacities and clouding of the eye's lens, known as cataracts, may form and block the passage of light through the eye. Some people are born with cataracts, but the incidence increases with age. They are not painful; in fact the only symptom is blurred, dimmed or double vision. Not all require surgery, but those large enough to cause serious visual problems require surgical removal of the lens, implantation of an intraocular lens and corrective glasses or contact lenses.

The increased lifespan of diabetics has increased the incidence of this disorder. Changes in the tiny blood vessels of the diabetic's retina can cause blindness. Abnormal blood vessels are formed, some may burst and the retina may even break loose from the back of the eye. Laser treatments to "seal" blood vessels or reattach the retina may help if undertaken early. Some diabetics, incidentally, do not experience vision loss.

Perhaps one in every seven or eight cases of blindness is due to this disorder, in which the transparent fluid inside the forward part of the eye does not drain normally and excess pressure is built up within the eye. If the pressure is not controlled, the delicate structure of the eye is increasingly damaged, resulting in blurred vision, a narrowed field of sight and eventually total blindness. Early symptoms may include blurred vision, halos around lights and reduced side vision. In the acute type, there is great pain as eye pressure rises quickly from blocked drainage canals. In the more common chronic type there is no pain and vision loss is gradual. Many cases are controlled very well by medication, but surgery is sometimes necessary. Early detection is important!

As the inner surface or lining at the back of the eye, the retina functions a little like the film in a camera. The macula is the part of the retina which forms the center of the "picture" and the sharpest image. Degeneration or breakdown of the retina may occur, especially with increased age. The disorder may be slow or rapid, but peripheral vision usually remains good. Magnifiers may help, and a few people may be helped by laser treatment to seal off blood vessels which have grown beneath the retina or to repair the macular's weak spots by removing worn-out tissue and allowing new tissue growth.

Frequently beginning as what is called "night