[Measurement of temporal summation of visual acuity with the use of a trial tachistoscope].
Visual acuity was measured in eighteen normal eyes of 10 subjects ranging from 20 to 30 years of age, using a modified tachistoscope. We changed the exposure time of the target (1-1,000 msec) or background luminance (0.1-200 cd/m2). The visual acuity rose with increasing exposure time. At background luminance over 10 cd/m2, the critical duration time was about 500 msec. However, at low luminance below 10 cd/m2, the critical duration was prolonged. This tendency was also seen when the pupil diameter was fixed at 3 mm with an artificial pupil. Similar by luminance detection, visual acuity was also determined by the product of background luminance and exposure time. From theses findings, we concluded that Bloch-Bunsen-Roscoe law was statisfied.
Niwa
K
K
Department of Ophthalmology, Tokyo Medical and Dental University School of Medicine, Japan.
Okuyama
F
F
Tokoro
T
T
D000328:Adult; D006801:Humans; D013997:Time Factors; D014792:Visual Acuity / Q000502:physiology*