Multifocal electroretinography allows physiological mapping of the central retina. The purpose of this study was to describe the spatial distribution of ERG-activity in patients with impairment of macular function which usually do not exhibit a pathologic Ganzfeld-ERG.6 patients with macular lesions due to uveitis (4), retinitis centralis serosa (1), and contusio bulbi (1) were examined using the multifocal ERG technique.In normal volunteers the response density of the multifocal ERG decreased with eccentricity according to cone density distribution. In eyes with impaired central vision the foveal and macular responses were markedly diminished while surrounding signals were of normal or moderately decreased amplitudes.With the multifocal ERG disturbances of macular function due to oedema and secondary structural changes were detected in the presented cases and the extension of the central lesions was estimated.