After-image Sentence Examples

The simplest is for the impression made by an observed object on the retina, the eye; in this connexion the term "after-image" (better "after-sensation") is used for an image which remains when the eye is withdrawn from a brilliantly lighted object; it is called positive when the colour remains the same, negative when the complementary colours are seen.

These images are created or produced not by an external stimulus, such as is necessary for a visual image (even the after-image is due to the continued excitement of the same organ), but by a mental act of reproduction.

For this no external stimulus is required, and as compared with the after-image it represents the objects in perspective just as they might be seen in perception.