• Fourteen patients with elevated intraocular pressures, normal visual fields, and asymmetry of disc cupping were examined using a number of psychophysical tests. The results suggest that color vision and visually evoked potentials show early disturbances, but a contraction of the visual field is variable.
Motolko M, Drance SM, Douglas GR. The Early Psychophysical Disturbances in Chronic Open-angle GlaucomaA Study of Visual Functions With Asymmetric Disc Cupping. Arch Ophthalmol. 1982;100(10):1632-1634. doi:10.1001/archopht.1982.01030040610011