Time-of-day variations in oculomotor function: II. Steady-state accommodation to square-wave gratings.
Time-of-day variations in both tonic accommodation and steady-state accommodation to a grating were assessed for 16 observers who were tested once in the morning and again 12 hours later. The mean night-time tonic accommodation was +0.5 D greater than the morning value. Square-wave gratings of 4.2 and 8.4 c/deg were presented to the observers at distances of 0, 1.07, 2.13, 3.2 D. Over-accommodation to far targets and under-accommodation to near targets occurred for both gratings. All values of steady-state accommodation were somewhat greater in the evening. Large individual differences were noted.
Amerson
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North Carolina State University, Raleigh 27695.
D000065:Accommodation, Ocular; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D009801:Oculomotor Muscles / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology; D013997:Time Factors