Abstract: There is disclosed apparatus and method for a test of eye dominance of human subjects for which on each 10-sec trial, one eye starts with a strong image that gets progressively weaker or does not get progressively stronger, while, at the same time, the other eye gets a weak image that gets progressively stronger. The initially strong image will always be seen at the beginning and eventually vision will flip to the other eye's view once that image has achieved sufficient strength to overcome the dominance of the initially strong stimulus (which itself is getting progressively weaker). The subject indicates recognition of the strengthening image and the time is recorded. Results show that the test provides a reliable measure of eye dominance which is seen to vary considerably among people within a sample of normal adults.