Infant vision testing by a behavioral method.

A behavioral method of screening binocular infant vision called forced choice preferential looking (FPL) has been developed. Clinical trials of the FPL test for young infants are reported here. The test aids nonspecialized personnel in early identification of bilateral ocular abnormalities and anomalies of binocular cooperation (strabismus). It is not possible to screen for monocular eye disease or amblyopia with this test. Modifications of the FPL test may offer new ways of assessing other aspects of visual function early in life.