What causes some users to see pink spots or shaded areas after using a visual display?
A. There are two phenomena that naturally occur in some individuals, after-image and the McCollough Effect. The pink spots are an “”after-image” which has been known for centuries, and disappear in seconds. The after-image actually is the complementary color of what is on the screen. People see pink because it is the complement to green, the common color of monochrome screens. The McCollough effect produces the complementary color and pattern of the screen and can last for several minutes. These phenomena are not unique to VDT use. With increasing use of color displays, reports of these phenomena should diminish.
