One hundred eighty-five patients with unilateral aphakic retinal detachment were studied to determine the frequency of retinal detachment in the fellow eyes undergoing cataract surgery. It was found to be four times higher than the frequency in those eyes that remained phakic (26% vs 7%). Despite the high incidence of detachment, 94% of the aphakic group had a final visual acuity of 20/60 or better in the second eye. At the time of surgery, the macula was still attached in only 17% of the 185 first eyes as compared to 57% of the 21 second eyes that developed an aphakic retinal detachment.