There is fascinating research at Johns Hopkins that could someday lead to treatment for degenerative eye diseases.
More than 2 million Americans have macular degeneration and another 8 million are at high risk. The best way to deal with it is to get an eye exam and get out in front of it.
If you stare at a dim light bulb without moving your eyes for about ten seconds, and then look at a blank wall or ceiling, you will likely see an afterimage of the light. Your brain may be playing tricks on your eyes.