The study enrolled 177 patients that had been admitted to the Research Institute of Eye Diseases of the Russian Academy of Medical Sciences for diagnostics and treatment - 134 patients with idiopathic macular hole and 43 patients with epiretinal fibrosis. All vitreomacular surgeries were performed between 2005 and 2011. Visual field defects were seen in all groups and were classified as either peripheral or paracentral, or concentric. The groups differed by the rate and the localization of the visual field defects. A direct relation between the severity of iatrogenic retinal damage, the extent of postoperative retinal thinning and the presence/type of visual field defects was established. Causes and risk factors of visual field loss after vitreomacular surgery have been identified and analyzed. Preventive measures for this complication have been proposed. Treatment efficacy varied depending on the causes. Acute peripheral visual field loss - "tunnel phenomenon" - as a result of significant iatrogenic local retinal damage during vitreomacular surgery has been described.