Fig. (1) (a) The average arterial dilation at the end of the flicker stimulus was diminished before (pre) and recovered markedly after (post) cyclophotocoagulation (p< 0.01). (b) The arterial dilation peak maximum during the last 10 sec of the flicker stimulus tended to be lower before (pre) than after (post) cyclophotocoagulation but the increase was not statistically significant (ns). (c) The arterial constriction peak maximum after the end of the flicker stimulus was very low before (pre) and increased significantly after (post) cyclophotocoagulation (p<0.05). (d) The average venous dilation at the end of the flicker stimulus increased only slightly and revealed no significant change between measurements before (pre) and after (post) cyclophotocoagulation (ns).