Stimulus & Macular Degeneration

The macula (Latin for "spot") is a spot on the retina that corresponds to the center of the visual field. This area contains the most photoreceptors, and it is our area of sharpest vision. Macular degeneration is often age-related.

Stimulus and Macular Degeneration

• Macular degeneration is not caused by too much stimulation (such as bright lights) or too little stimulation (reading in the dark), as was once thought. It is age-related, caused by a buildup behind the retina. Macular degeneration causes a very characteristic response to stimulus--a dark spot in the center of the visual field.

Causes and Effects

• Stimulus is not completely blocked by macular degeneration. The dark spot in the center of the visual field makes it difficult to read and to recognize faces. Peripheral vision stays intact but is reduced in quality and color. People with macular degeneration learn to look at the world out of the corners of the eye--sideways instead of straight on.

Types of Macular Degeneration

• There are two types of macular degeneration: dry and wet. Dry macular degeneration is caused by a buildup of drusen between the retina and the choroid. Wet macular degeneration is caused by new blood vessel growth between the retina and choroid. Both can sometimes be helped with laser procedures.