A Sargon user-defined Octopus program was devised to quantitate central visual field changes following laser photocoagulation for choroidal neovascular membranes. The program was found to be reliable in testing the nine patients studied. All patients had areas of improved and areas of reduced sensitivity. The areas of reduced sensitivity were larger than the areas of improved sensitivity (P < 0.05). with a net negative change in sensitivity found in all cases. However, the improved areas tended to be closer to fixation than the worsened areas. Quantitative static perimetry can be applied to the study of choroidal neovascular membranes. It is an important visual parameter that should be evaluated in future studies of these membranes, especially with regard to wavelength efficacy in photocoagulation therapy. RETINA 8:24-29, 1988.