Density of human cone photopigments as a function of age

The density difference between fully bleached and fully dark-adapted retinas was assessed for 77 eyes (47 subjects) in the age group 13-50 yr. No significant change in density was found as a function of age. The time constant of pigment regeneration was also found to show no age effects up to the age of 50 yr. These findings are at odds with another study on the density of foveal cones.