Correlation between performance and cone density across polar angles.

Contrast thresholds (y-axis) were averaged across three observers reported in Cameron, Tai, and Carrasco [5]. Thresholds were obtained for stimuli at 4.5° eccentricity, above (gray), below (blue), left (red), and right (green) of fixation as indicated by the legend. Cone density along the four meridians are the average values reported by Song et al. [41] at 4.5° eccentricity. (For right and left, cone density was averaged for the nasal and temporal retina, since observers performed the psychophysics task binocularly). Error bars indicate one standard error across 10 observers (cone density) and 3 observers (contrast thresholds).