About one in 200 Americans over age 55 suffers from tunnel vision, as a result of diseases such as retinitis pigmentosa (RP) and glaucoma. RP can begin to affect vision in one's teen years and may become quite severe tunnel vision by middle age.
Residual tunnel vision occurs when peripheral or side vision is destroyed, leaving only a small window of central vision. The field of view of these people can be like looking through the tube of a roll of paper towels. Thus, tunnel vision can often cause the individual to bump into or trip over obstacles. Navigating city streets or buildings can be quite challenging. For a person with tunnel vision, finding a misplaced item is like searching for a key in a dark room using a tiny flashlight.