Can spatial resolution reveal individual differences in the L:M cone ratio?

摘要: Abstract We measured spatial resolution in the parafovea for targets designed to isolate either long-wavelength (L) or middle-wavelength (M) cones. Landolt C optotypes were presented 100 ms on a calibrated monitor at an eccentricity of 5° left right fixation. There large individual differences ratio obtained with L that M targets, and we suggest these reflect variations relative sampling densities cones parafovea. In Experiment 1, contrast thresholds varying size. Among 10 unselected observers, there was threefold variation smallest targets. Experiments 2 3, held constant varied size, order establish minimal target could be discriminated each two classes cone. 2, groups selected basis their settings flicker-photometric test, showed highly significant difference acuities task. female carriers protan deutan deficiencies, classified only sons’ phenotypes, also all three experiments, strong correlation between measure sensitivity long- light.