Electrophysiologic examinations of the retina and optic nerve were carried out in 44 patients with extensive detachment of the retina involving the macular area. The aim of the research was to elucidate the possibility of predicting vision acuity recovery from electrophysiologic characteristics before and after surgery. Diagnostic value of various parameters was assessed. The capacity to reproduce electroretinogram rhythm was found to be the most informative prognostic criterion. Preoperative electroretinogram rhythm 25 Hz and higher permits expecting vision acuity recovery higher than 0.6 diopters.