Holding two index fingers in front of the eyes can create the perception of a floating finger sausage.This best illustrates the effect of

Question

Quizplus · Accepted Answer

Retinal disparity refers to the slight difference in images projected onto the two retinae because of the distance between the eyes. This creates a sense of depth perception and is what causes the illusion of a floating finger sausage when holding two fingers in front of the eyes. The other options (relative height, interposition, relative motion) do not apply to this specific illusion.

Holding Two Index Fingers in Front of the Eyes Can