Related Experiment Video
Updated: Jul 29, 2026

A Novel Light Damage Paradigm for Use in Retinal Regeneration Studies in Adult Zebrafish
Published on: October 24, 2013
Foveal dark adaptation, photopigment regeneration, and aging
1Program in Psychobiology and Neuroscience, Florida State University, Tallahassee.
Abstract:
Foveal dark adaptation in 58 subjects and photopigment regeneration in 60 subjects from 10-78 years of age exhibit parallel slowing of recovery rate with increasing age, with significant correlation of the two functions among individuals. The data are suggestive of an initial slight decline in rate before age 50, followed by a greater decline occurring at different ages in different individuals. Longitudinal data for one subject from age 40-65 show an increase in pigment regeneration time constant consistent with this idea. Foveal sensitivity and photopigment density both decrease with increasing age and are significantly correlated among individuals, although sensitivity declines more with age than does photopigment density. In contrast to earlier proposals based upon the Rushton-Dowling equation, we found no universal constant of proportionality to relate log relative threshold to photopigment within our population.
More Related Videos
Related Concept Videos
The Retina
Photoreceptors and Plant Responses to Light
Unrenewable Cells
Photoreceptors
The retina is composed of several layers and contains specialized cells called photoreceptors. The photoreceptors (rods and cones) change their membrane potential when stimulated by light energy. There are two types of photoreceptors—rods and cones—which differ in the shape of their outer...
Pigmentation
Melanin occurs in two primary forms: eumelanin that provides black and brown pigment and pheomelanin that provides red color. Dark-skinned individuals produce more melanin than those with pale...
Anatomy of the Eyeball
Photoreceptors and Visual Pathways

