Updated June 09, 2015.

Definition:

FPT is the standard test used to evaluate visual acuity in children. Visual acuity is the ability of the eyes to focus images on the macula, the part of the eye that handles detailed vision. FTP was originally designed to diagnose amblyopia ("lazy eye") in infants.

During the test, each eye is covered and then uncovered. The doctor may hold a small object or picture in front of the infant or child.

When one eye is covered, the doctor evaluates how well the uncovered eye maintains fixation on the object. The test results give the doctor an idea of which eye sees better, if there is a difference between the two.