Chromograms of color normals and multiple sclerosis patients.

The Gunkel chromograph was tested on 81 volunteers with normal color vision as indicated by screening with Ishihara plates and the panel D-15. Most of these color normals located their neutral area superior to the geometric center of the chromogram. A minority located their neutral area at the geometric center. Recognition of this variation may prevent misdiagnosis of chromographs of patients suspected of having color vision defects. All 29 eyes with history and VEP findings consistent with optic nerve demyelinization had enlargement of the neutral area, even though visual acuity could be corrected to 20/20.