Factors Affecting Vision

Author: E.E. Kimberly

The ability of the human eye to see depends on the size of the object to be seen, the brightness to which it is illuminated, the time of its exposure to the eye, and the brightness of the background against which it is seen. The brightness of an object depends on the amount of light falling upon its surface. It also depends on the ability of that surface to reflect the light. An object upon which light falls is said to be illuminated.