Periodic alternating nystagmus clearing after cataract surgery.

A 60-year-old man developed periodic alternating nystagmus in association with decreased vision due to cataracts. Prior to surgery, vision was limited to hand motion only in both eyes. An extracapsular cataract extraction with insertion of a posterior chamber intraocular lens was performed in the patient's left eye. On the first postoperative day, vision was 20/60 in the left eye and the nystagmus was absent with both eyes open. Periodic alternating nystagmus that occurs with poor vision is related to a loss of fixation. Surgery aimed at improving the visual status may be effective in extinguishing the nystagmus.