The Pulfrich phenomenon in optic disc drusen.

Optic disc drusen are hyaline bodies in the optic nerve head of unknown aetiology,1 which are present in approximately 2% of the population.2 Reduced visual acuity associated with optic disc drusen is rare, although visual field defects are common in cases of visible drusen.3 4 Although the condition is frequently bilateral, asymmetry is usual.5 We report a case of a patient with disabling visual symptoms associated with optic disc drusen. These were found to result from the Pulfrich phenomenon and were resolved by prescribing an appropriate ophthalmic tint. A 20-year-old woman was seen in our optometry clinic and subsequently examined by a consultant ophthalmologist. She was moderately myopic, with good visual acuities (6/5 OU), no history of ocular disease and showed no symptoms …