What is meant by the term negative afterimage and what does the phenomenon indicate?

Question

Anatomy and Physiology

Answer 1

Negative afterimage is the result of fatigue in the photoreceptors. After prolonged exposure to bright lights or great contrast in the brightness of objects in the field of view, the photoreceptors will continue to send signals even when the eyes are closed, resulting in the reversal of the image you just looked at. Bright white will appear dark black, dark black will appear bright white and it will seem like your looking at this projected image on the back of your eyelid.

Look at a light bulb in front of a black backdrop for a little while then turn away and close your eyes. It will seem like you're looking at a bright wall with a very dark spot.