The antiepileptic drug vigabatrin causes an asymptotic concentric contraction of the visual field in 30 to 40% of the patients. The visual field loss seems to be correlated with the cumulative dose of vigabatrin and is not reversible. The cause of this field loss is located in the inner retina (the horizontal and/or amacrine cells). The exact mechanism is still unknown. Though abnormalities in electrophysiology and colour vision are found, regular visual field examination remains the cornerstone in detecting visual field loss. A careful judgement has to be made in individual patients before starting or continuing vigabatrin medication.