The Worth Four Dot Test: Is it Really “Worthless”?

The Worth 4 Dot Test was introduced by Claude Worth in 1903 as a test measuring binocularity. Hardy, in 1937, incorporated the lights of Worth into a hand-held flashlight. Further modifications were made by Behrens, Muenzler, and Raab. The W4D has become a standard test of sensory function in most strabismus practices. However, the targets have not been standardized in their manufacturing. Since the target size determines the visual angle the...