Results 1 to 10 of about 185,847 (298)

The early phase of dark adaptation

Vision Research, 1972
Abstract 1. Immediately after a small bleach (6 per cent) the threshold is 50 times higher than expected of rhodopsin but soon returns to the rhodopsin level. This early dark adaptation curve is the same if the bleaching energy ( It ) is the same no matter if t is 0.5 sec or 0.5 min. 2.
W A, Rushton, D S, Powell
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Dark adaptation of the frog's rods

Vision Research, 1973
Abstract Using sodium aspartate Ringer's and isolated frog retinas we have recorded gross potentials from the frog's 502 (rhodopsin) rods. Substantial dark adaptation is seen at the receptor in the isolated retina in which little or no rod pigment regeneration occurs.
D C, Hood, P A, Hock, B G, Grover
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Dark Adaptation to Intermediate Levels and to Complete Darkness*

Journal of the Optical Society of America, 1954
The course of the change of the visual threshold was measured during adaptation from a high-luminance level to various lower luminance levels and to darkness. Measurements were both foveal and parafoveal. The foveal measurements show photopic function only, while the parafoveal measurements result in duplex curves at the lower luminances.
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The impact of dark adaptation on photoscreening

Journal of American Association for Pediatric Ophthalmology and Strabismus, 2002
Some previous studies have used different dark adaptation periods to achieve adequate pupil dilation for photo refraction. Because efficient use of time is important in screening programs, we investigated how dark adaptation affects the quality of eye photographs.This prospective study was done on 2 groups.
Altuğ, Cetinkaya, Sibel, Oto, Pinar, Aydin   +2 more
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Dark-adaptation: A new hypothesis

Vision Research, 1964
Abstract Bright lights cause an elevation of the visual threshold which persists after the light is turned off. It is suggested that this is caused by the receptors becoming noisy, rather than by weakening of their responses. Apparently the presence of bleached photopigment causes the receptors to show effects similar to those induced by light, even ...
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Dissecting the dark-adapted electroretinogram

Documenta Ophthalmologica, 1998
Although gross recordings of the ganzfeld flash-evoked electroretinogram (ERG) can potentially provide information about the activity of many, if not all, retinal cell types, it is necessary to dissect the ERG into its components to realize this potential fully.
J G, Robson, L J, Frishman
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Dark Adaptation in the Turtle, Pseudemys

Brain, Behavior and Evolution, 2008
The present study uses a behavioral avoidance paradigm to trace the course of dark adaptation in the turtle, Pseudemys. The results indicate that the turtle has a multiprocess visual system whose spectral sensitivity shifts from a maximum in the long-wavelength region when light-adapted, to a maximum in the shorter wave-lengths after prolonged dark ...
J H, Maxwell, A M, Granda
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Increment Threshold and Dark Adaptation*

Journal of the Optical Society of America, 1963
The increment threshold ΔI as a function of the background field I is independent of the amount of bleaching in rods and cones; the value of ΔI for rods depends upon the activity of their neighbors. The absorption of one quantum always elicits a rod signal, but its effectiveness depends upon the threshold for signals in the summation pool.In dark ...
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DARK ADAPTATION IN MONGOLS

Journal of Intellectual Disability Research, 1967
A W, Griffiths, J, Behrman
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THE EFFECT OF HUE ON DARK ADAPTATION

Optometry and Vision Science, 1943
The writer believes that the reported reduction in time necessary to dark-adapt the eyes by wearing red goggles for a period of approximately 30 minutes is due to the much reduced brightness of the visual field as viewed through the goggles and not to the wave-length region involved.
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