The retina lines the inside of the eye, passing visual information to the optic nerve. An area of the retina, called the macula, is responsible for central vision. Two types of macular degeneration result from damage to the macula: Dry macular degeneration occurs from cell damage in the macula, and the wet form occurs when blood vessels bleed behind the macula. Both types may result in permanent vision damage, though knowing early warning signs of the condition may help prevent vision loss.
Central Vision
Dry macular degeneration will slowly damage the central vision, the vision used for reading, driving and recognizing faces. Early signs may appear as a blur or smudge in the middle of vision. For some people, vision may improve in good lighting, according to the National Eye Institute. However, as the condition worsens, the blurred central vision will worsen, until the person has a complete blind spot in the central vision. In this situation, people rely on peripheral vision to perform basic daily activities.
Lines
Early signs of wet macular degeneration appear when looking at a straight line, but the line appears curved or bent, explains the U.S. National Library of Medicine. Many people first notice this in objects seen every day, such as street lights. Additionally, during a visit with an eye doctor, the doctor may ask a person to look at an Amsler grid, a checkerboard-grid of lines, and if any of the straight lines appear distorted, this will help the doctor determine the extent of vision damage. In most people, even with treatment, the distorted vision will not improve, which makes daily tasks, such as reading, difficult or impossible.
Drusen
During an eye exam, the doctor will dilate both pupils so that he can examine the back of the eye. He may notice drusen, one of the early warning signs of dry macular degeneration. Drusen appear as yellow deposits under the retina. Though doctors and researchers do not understand the link between these deposits and macular degeneration, they do know that when a person has more drusen, or large drusen deposits, they have a much higher risk for developing dry or wet macular degeneration, according to the National Eye Institute.
