Contrast sensitivity throughout adulthood

Previous studies of spatial contrast sensitivity in adulthood have produced conflicting results. To clarify the situation, we measured contrast sensitivity functions on a large sample of adults (n = 91), ranging in age from 19 to 87. All observers were free from significant ocular pathology and were individually refracted for the test distance. Sensitivity for stationary gratings of low spatial frequency remained the same throughout adulthood. At higher spatial frequencies, sensitivity decreased with age beginning around 40 to 50 years. When a low spatial frequency grating was drifted, young adults' sensitivity improved by a factor of 4-5 over sensitivity to a static grating; this motion enhancement was markedly diminished in adults over 60 years, implying an impairment of temporal processing in the elderly. Reduced retinal illuminance characteristic of the aged eye could account for a large part of older adults' deficit in spatial vision, but appeared to play little role in their deficit in temporal vision.

Psychophysics of reading XX. Linking letter recognition to reading speed in central and peripheral vision

http://gero.usc.edu/AgeWorks/spring_session2015/tdl/gero510/changes_lect/AgingandVision.pdf

Aging and vision.

Neural bases of visual deficits during aging.

The visual contrast sensitivity (the reciprocal of contrast threshold) was studied as a function of age. Psychophysical measurements of binocular and monocular contrast thresholds were made for 33 normal observers at spatial frequencies within the range 0.5 to 40 cycles/degree. The observers were divided into three different age groups: young, middle-aged, and old subjects with the age ranges 6--10 years, 20--40 years, and 60--70 years, respectively. All observers had healthy eyes, normal vision, and Snellen visual acuity of 1.0 or better in both eyes. In all groups, contrast sensitivity for binocular and monocular viewing peaked at a spatial frequency around 3--5 cycles/degree and showed the typical attenuation at low and high spatial frequencies. The binocular contrast sensitivity was higher than the monocular. There was no significant difference between young and middle-aged subjects with regard to contrast sensitivity. Subjects aged 60 years or more showed significantly lower contrast sensitivity than younger subjects for most spatial frequencies above 4 cycles/degree. We may thus conclude that both the binocular and monocular contrast sensitivity seemed independent of age within the range of 6 to 40 years. For higher ages studied (above 60 years), there was a loss of sensitivity in the middle and high frequency regions.

Björn Lundh

Papers

Age variations in normal human contrast sensitivity.