A Ganzfeld stimulator for electroretinography.

The design of a ganzfeld stimulator for electroretinography affects both clinical results and ease of operation. Several advantageous design differences from a recently described ganzfeld stimulator are (1) close proximity of the flash electrode to the surface of the sphere to increase the intensity and uniformity of the stimulus; (2) provision for interposing color filters in the background light; (3) use of a diffusing filter in the background light; and (4) placement of the stimulus flash anteriorly to avoid uneven illumination of the retina. Details of construction are proveded for two models and the specific advantages of each design are noted.