Subjective visual perceptions during intraocular surgery under local anaesthesia: a review

Subjective visual perceptions during intraocular ophthalmic surgery under regional anaesthesia are now well recognised. They range from simple light perception to seeing vivid colours, intricate movements, flashes and instruments. Surgeons, anaesthetists and patients should be aware of these phenomena. Although the majority of the patients find visual perceptions bearable some may be frightened. Preoperative counselling should therefore be offered to patients. This article reviews the range and clinical implications of subjective visual perceptions during intraocular surgery and explores the mechanisms behind their genesis.