The Pulfrich effect in anisometropic amblyopia and strabismus.

Using a device based on the Pulfrich effect, we examined 70 patients with various strabismus problems and 20 normal subjects for gross stereopsis. We found an excellent correlation between this dynamic stereopsis test and random dot stereograms. Additionally, in several instances the Pulfrich device was easier to use and interpret correctly than random dot stereograms. The Pulfrich effect can be elicited reliably in patients as young as 3 1/2 years of age. Three patients with anisometropic amblyopia and stereopsis were found to possess a spontaneous Pulfrich effect.