Contrast sensitivity and disability glare in the middle years

Abstract

Spatial contrast sensitivity and disability glare were measured in a large sample (n = 90,30 per decade) of middle-aged subjects, aged 21-50 years, who had clear media and were ophthalmologically normal. We found no significant differences in the contrast sensitivities as a function of age in the middle years for (1) gratings generated on a monitor; (2) interference gratings generated in the retinal plane; (3) gratings in the presence of glare; and (4) mesopic increment thresholds with and without glare. The large sample size provides sufficient statistical power (0.8) for one to conclude that contrast sensitivity, optical quality, and foveal neural sensitivity are unlikely to vary more than 0.1 log unit between the ages of 21 and 50 in ophthalmologically normal subjects with clear media.

Mesopic contrast sensitivity in the presence or absence of glare in a large driver population

“…This finding is consistent with those described by Scharwey et al [25], who found that mesopic contrast acuity and glare sensitivity, measured using the Mesotest II, deteriorated in an age-dependent way in 117 healthy subjects. We are in agreement with Harrison et al [12] who found no significant differences in the sensitivity increment in the absence or presence of glare as a function of age across the middle years (21-50 years) in ophthalmologically normal subjects using sinewave gratings to measure the mesopic contrast sensitivity at four low spatial frequencies. We also observed homogenous results in the middle age groups (21-50 years) of our population.…”

Understanding disability glare: light scatter and retinal illuminance as predictors of sensitivity to contrast

“…As expected, those aged fifty years or older had significantly larger k values (mean = 57.14) than younger participants (mean = 33.46), t(38) = 3.90, p < .01. In agreement with previous literature, this finding indicates that scatter within the eye increases over the age of fifty years [34][35][36].…”

“…Given the well-established decline in visual function with age, both as a result of changes in the optics of the eye [34][35][36][43][44][45] and neural changes [46][47][48][49], it seems unlikely that the discrepancy in the older group's performance would be due to additional protective factors. A more likely explanation would be that the contrast threshold curve, upon which the estimations of retinal sensitivity are based, is not entirely representative for older observers.…”

Does Age-Related Decline in Ability Correspond with Retirement Age?

“…It is worth noting there is some disagreement as to how quickly color vision declines -for example, see Schieber (2006). 23 Higgins (1988), Harrison (1993), Jackson et al (1997), Jackson and Owsley (2000), and Schieber (2006). 24 Fozard and Salant (2001).…”