Contrast sensitivity in children and adults.

Abstract

analyse change with age. This series may form the basis for assessment of contrast sensitivity in children. Materials and methodsCaucasian children aged 3 to 15 years and adults 18 to 29 years were subjects in this study. In each age group approximately equal numbers of males and females were tested. All subjects were volunteers. 86% of them were given an ophthalmological examination. Those over 6 years were required to have an uncorrected Snellen acuity of 6/6 or better for distance and those under 6 years an uncorrected acuity of 6/9 by the E test. The 14% not given an ophthalmological test were distributed over all age groups.Vertical sinusoidal gratings were generated in the conventional way2 on a display monitor (Tektronix 604 P31 fast-decay phosphor). The average luminance was 9 cd/M2 and varied from peak to trough between 14 cd/m and 4 cd/M2 giving a maximum contrast value of 0 5, contrast being defined as (Lmax -Lmin/Lmax + Lmin) whtr8-Lmax and Lmin are the maximum and minimum luminances respectively of the gratings display. Observers sat 1 metre from the display, which was viewed binocularly with natural pupils through a circular window mounted on the face of the monitor such that the display subtended 6 degrees. The surround was approximately matched for luminance and colour. Room luminance was approximately 2 cd/M2. An experimenter sat beside the subject and showed samples of gratings, varying the spatial frequency and contrast. The subject's task was to report when any lines were visible. Special care was taken to ensure the instructions were understood. Subjects were asked to keep their heads straight and at the measured distance; this was checked on a video-863 on 12 May 2018 by guest. Protected by copyright.

Contrast sensitivity and disability glare in the middle years

“…This finding is consistent with the results of other studies 6 0 and indicates that there were no subclinical age-related increases of light scatter detectable by our tests in this age group. This conclusion is also consistent with the trend of the data in the study of IJspeert et al, 3 ' who used a more direct compensation method to assess forward ocular light scatter. However, one study 32 found a significant change in disability glare (incrementthreshold technique) between the age groups of 20-25 (n = 10) and 40-45 (n = 10) years.…”

“…In the five increment-threshold studies of disability glare and age reviewed by Vos,3 ' the predicted change in Al ranged from 0.06 log to 0.21 log, depending on the study, from age 25 to age 45. Our study had a power of 0.8 to detect a 0.05-log-unit change at the 0.05 level of confidence for log IIAL Therefore the lowest of the age factors would be more consistent with our results.…”

“…The function relating spatial CS to age has not been well defined, particularly in the middle years. Although several studies have shown that CS increases from infancy to a maximum during adolescence" 3 ' 4 "' and decreases for older normal subjects (aged 60-80 years), 7 9 ' 3 sample sizes have not been adequate to determine when the decrease starts. Furthermore, existing studies do not specify the limits of the change that would go undetected in the middle-aged group.…”

FACT contrast sensitivity as a diagnostic tool in glaucoma

“…In the past, several authors studied spatial contrast sensitivity with computer-based systems and plates [10][11][12][13][14][15][16][17][18][19][20][21][22]. As contrast-sensitivity testing was introduced into clinical practice and clinical research, the test apparatus usually consisted of computer generated visual images as test targets and a software-controlled threshold measurement procedure.…”

Development of Visual Acuity and Contrast Sensitivity in Children

“…The results show that CS becomes adult-like somewhere between 7 years 3 and 9-12 years. 41 Some studies had small sample sizes at the critical ages 5 while others grouped the children into rather large age spans, 41 , 42 which makes it difficult to define exactly the age at which vision becomes fully adult-like. Other studies did not report statistics.…”