Fifty-seven eyes of 49 patients with senile retinoschisis were treated by argon laser photocoagulation and followed up for 3 to 6 years. In most of the treated eyes the retinoschisis either completely or partially collapsed and in none did the retinoschisis or loss of visual field progress further. No long-term complications due to the treatment were noted. In none of the treated eyes did retinal detachment develop. In view of this the indications at present for argon laser treatment in retinoschisis may be extended to include any case in which the retinoschisis progresses beyond the equator and visual field loss continues. This may prevent further visual field damage and other rare complications of slowly progressive retinoschisis and facilitate the many years' follow-up of elderly patients with retinoschisis who develop cataracts.