[Meridian photopic and mesopic color perimetry in normal, young and presbyopic subjects]

The authors report their results of static color perimetry performed with the Harms perimeter. Photopic testing was performed among 10 young normal subjects and then with 10 presbyopes with otherwise unremarkable ocular examinations. Mesopic testing was done with 9 young subjects. Three thresholds of perception were stated: achromatic, minimally colored, and chromatic. Using photopic testing, red perception was far more sensitive in central vision, and the inverse was found in peripheral vision. Tritanomaly exists in the fovea, and at 15 degrees nasal to the fovea, the 3 color curves cross. In presbyopia, age is responsible for decreased sensation of red and green compared to white, and, all color perception disappears beyond the blind spot. The decrease in sensitivity for blue is even more significant realising a foveal tritanopia. At a lower luminance level, mesopic testing revealed an achromatic threshold for green and blue with central lowering of sensitivity. Deductions are made concerning the anatomo-physiologic mechanisms involved.