[Erythropsia in a patient with lens implant. Physiologic and electrophysiologic study].

A case of snow erythropsia is described in a patient with pseudophakia (Binkhorst four loop len). Symptoms of the condition lasted a week and allowed us to define psychophysic and electrophysiological findings. Morphoscopic night threshold was raised (0,28 b/hm 2). Resistance to glare was very low. In the study of colour vision, answers for Beyne's lantern lights were: pink orange for white; grey for blue; purple for red; red for orange; white for green. Ishihara and Farnsworth tests showed a defect of the red-green type. With the Nagel anomaloscope the matching of colours was normal (Rayleigh match). Electrophysiological study showed a low value of the standing potential of the eye and a normal electroretinogram. It seems that the colour defect in erythropsia is a glare phenomenon due to high luminance.