Reports of the Committee on Vision 1947-1990 (1990) / Chapter Skim
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Dark Adaptation and Night Vision
Dark Adaptation and Night Vision
Pages 33-42
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From page 35... ...
It was assumed that it would be possible to prepare a report comparable to the reviews of scientific literature that appear from time to time in various scientific journals. During the development of the project, according to the author, it became apparent that the initial plan would have to be modified, and the decision was made to prepare informative abstracts of the original articles arranged in chronological order of their appearance.
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From page 36... ...
In response to the demands of two wars, biochemical and electrophysiological research have received increased support. The requirement that specified levels of dark adaptation be maintained, the need for finding an alternative for total darkness in becoming dark adapted, and the hope of speeding up dark adaptation have resulted in widespread efforts to identify and establish the ranges of the variables affecting the instantaneous threshold and the subsequent course of dark adaptation.
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From page 37... ...
This summary notes that the project involved the preparation of a bibliography, the review of papers cited in this bibliography, with the preparation of evaluative abstracts of each, and finally, the publication of a paper summarizing the status of knowledge on this and closely associated topics. For a number of reasons it proved impossible for the working group to carry this task through to completion.
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From page 38... ...
Consequently, exploratory experiments have been undertaken with much larger flash patches to investigate the role played by this factor. In all of this work, the site of the beam entering the eye has been restricted by artificial pupils, which are smaller than the natural pupil, so that variations in the size of the natural pupil have not influenced the results.
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From page 39... ...
The role played by stray light has to be taken into consideration; this is particularly important in the case of a bright patch subtending a small solid angle and having a dark background. The small number of photoreceptors stimulated director by the bright patch might well have a negligible effect on pupil constriction in comparison with the effect produced by the thousands of photoreceptors that are stimulated only by the stray light in the eye.
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From page 40... ...
60 pp. no figures no tables 69 references Availability: National Technical Information Service (NTIS)
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From page 41... ...
In recent flash blindness studies, rather short-duration blinding flashes have been used, sometimes as short as the microsecond range, but now even shorter pulses are available. Lasers with pulse durations as short as perhaps 30 nanoseconds have been used to produce retinal lesions.
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From page 42... ...
recommendations for the development of night vision screening tests. The first two objectives were addressed by convening a symposium at Brooks Air Force Base in 1985.
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