A tricolor light source for stimulation and adaptation in electroretinography.

A Ganzfeld light source, fitted on an electroretinogram contact lens, is described. The light source can provide blue, green, or red flashes with intensities over a range of 3.6 log units. It can also be used to provide a continuous light-adapting background in each of the above-mentioned colors, simultaneously presenting the possibility of emitting flashes. The control unit and the light source can be powered by a small battery pack.