Spectral threshold: measurement and clinical applications.

Photopic spectral sensitivities for a foveal target on a white background are measured for 18 normal eyes, and the results are explained in terms of the function of retinal ganglion cells. Averaged results for diseases such as glaucoma, optic atrophy, tobacco amblyopia, and retrobulbar neuritis are reviewed, and an analysis of the change in shape of the spectral sensitivity curve in these diseases is presented. It is shown how the location of disease sites may be related to characteristic changes in spectral sensitivity.