Short-wavelength automated perimetry (SWAP) is a more sensitive test than standard achromatic perimetry for early loss of vision due to glaucoma and other ocular and neurological diseases. SWAP is also more successful for detecting changes in vision as glaucoma progresses. Results from various visual function-specific tests, including SWAP, suggest that there are individual differences in ocular hypertensive and glaucoma eyes in the subtype of ganglion cell first affected. However, the disease targets the same retinal area for all function-specific tests that show a deficit in a given individual. Psychophysical tests of vision are critical to understand glaucoma's effect on retinal ganglion cells, to verify the success or failure of treatment including new neuroprotective agents, and to determine the relationship of genetic markers for glaucoma to the presence and progress of the disease.