The Effect of Light-Flashes during the Course of Dark Adaptation

1938 ◽  
Vol 51 (4) ◽  
pp. 717 ◽  
Author(s):  
E. A. Suchman ◽  
H. P. Weld

1938 ◽  
Vol 51 (3) ◽  
pp. 540 ◽  
Author(s):  
Laura K. Allen ◽  
Karl M. Dallenbach






2019 ◽  
Vol 2 (9) ◽  
pp. e1911944 ◽  
Author(s):  
Katherine A. Kaplan ◽  
Meital Mashash ◽  
Rayma Williams ◽  
Holly Batchelder ◽  
Lolly Starr-Glass ◽  
...  


1978 ◽  
Vol 206 (2) ◽  
pp. 151-156 ◽  
Author(s):  
J. D. Brammer ◽  
Peter J. Stein ◽  
Ronald A. Anderson




1961 ◽  
Vol 44 (6) ◽  
pp. 1143-1158 ◽  
Author(s):  
Eberhard Dodt ◽  
Karl Heinz Jessen

The effect of light and dark adaptation on the electrical activity in two species of nocturnal gecko, Hemidactylus turcicus and Tarentola mauritanica was studied. The electroretinogram of both species changes from the scotopic type in the dark-adapted state to the photopic type after strong light adaptation. For the scotopic response fusion frequencies up to 18 flashes per sec. are obtained in both species. For the photopic response fusion frequencies up to 50 flashes per sec. are seen in Tarentola, and up to 25 flashes per sec. in Hemidactylus. Proceeding from dark to light adaptation the increment threshold (dI) is measured at different levels of adaptive illumination (I). At low levels of illumination the dI/I ratio is found to be small and at high levels of illumination to be large. No difference in the dI/I ratio is obtained for test lights of 462 and 605 mµ. During dark adaptation the change of threshold after exposure to moderate and weak lights (up to 103 times dark threshold) is rather fast. After light adaptation to strong light (106 times dark threshold) duplex dark adaptation curves are seen with a break separating a fast and a slow phase of dark adaptation. The significance of these results from a retina which possesses sense cells of only one type is discussed.



1982 ◽  
Vol 96 (1) ◽  
pp. 389-403 ◽  
Author(s):  
R. H. DOUGLAS

1. The function of photomechanical movements in the retina of rainbow trout (Salmo gairdneri) was investigated by determining both the effect of light on the level of extractable visual pigment, and the electroretinographic b-wave sensitivity, during various stages of photomechanical light and dark adaptation. 2. Dark-adapted fish, light-adapted fish, and dark-adapted fish exposed to ten minutes direct sunlight had on average visual pigment concentrations of 100, 82 and 36% respectively. 3. The intensity of illumination required to bleach a specified amount of visual pigment in the light-adapted retina was found to be 1.29 log units higher than that needed to bleach the same amount of visual pigment in a dark-adapted eye. 4. The level of extractable visual pigment was observed to be relatively constant over natural twilight periods. 5. A close temporal correlation was observed between the time course of electroretinographic adaptation, measured by the b-wave sensitivity, and photomechanical changes. 6. All these observations tend to support the hypothesis that photomechanical movements serve, at least in part, to protect the rod visual pigment from overstimulation in the light-adapted retina.



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