[The influence of anamorphotic image formation on the visual evoked cortical potential]

The correction of astigmatism by spectacle lenses involves anamorphotic image formations and produces distortion of retinal images, putting strain on the sensory part of fusion. These distortions were artificially produced by anamorphotic telescopes in a group of emmetropic volunteers. In binocular visually evoked cortical potential (VECP), a transient increase in amplitudes was recordable after application of the anamorphotic distortions. The removal of anamorphotic telescopes resulted in a distinct decrease in amplitude, followed by an overshoot increase before recompensation to pretest values occurred. The amplitude reactions observed are suggested as being an objective indicator of the cortical fusion mechanism.