Dark-Adaptation and Psychology

Godding, E. W.

doi:10.1016/s0140-6736(45)91603-5

Cited by 2 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…They considered that the best criterion of dark adaptation for the detection of vitamin A deficiency is the final rod threshold. Furthes development of instruments for testing dark adaptation were described by Godding (1945). Livingston (1944, 1, 2) devised a method of taking perimetric measurements with the fully dark-adapted eye and demonstrated the impairment caused by lack of oxygen.…”

Section: Foods Containing Ascorbic Acidmentioning

confidence: 99%

European Conference of the Nutrition Society

Barcroft¹

1947

Proc. Nutr. Soc.

View full text Add to dashboard Cite

Section: Foods Containing Ascorbic Acidmentioning

confidence: 99%

European Conference of the Nutrition Society

Barcroft¹

1947

Proc. Nutr. Soc.

View full text Add to dashboard Cite

“…Withoutt this, differenices in observation and interpretation by different workers ,are bound to occuLr. Such control can only be achieved by the standardization of such conditions (see also Godding, 1945). This has been attempted and the results applied to the present instrumenit.In testing dark adaptation it is necessary to emnphasize that wve are not testing ability to carry out actual Visual tasks at night (described by Livingston as "night vistual capacity", 1942).…”

mentioning

confidence: 99%

mentioning

confidence: 99%

An Instrument for Testing Dark Adaptation

Godding¹

1945

Proceedings of the Royal Society of Medicine

View full text Add to dashboard Cite

KNOWVLEDGE of the phenomenon of (lark adaptation is no0W sufficient to enable the various factors which condition it to be brought under control and to make its evaluation possible. Dark adaptation is defined as the process by which the eye adapts itself to a change in illumination from high to low intensity, the change being accompanied bv an increase in the sensitivity of the eye.The practical measLuremenet of dark adaptation by means of threshold measuLrements hcas been found to be dependent on many external phvsical conditions apart from biolog,ical variations in the sUbjectS themselves. It is, therefore, stressedl that one of the first requiisites for the scienitific investigation of the sutbject is the control of these condlitions. Withoutt this, differenices in observation and interpretation by different workers ,are bound to occuLr. Such control can only be achieved by the standardization of such conditions (see also Godding, 1945). This has been attempted and the results applied to the present instrumenit.In testing dark adaptation it is necessary to emnphasize that wve are not testing ability to carry out actual Visual tasks at night (described by Livingston as "night vistual capacity", 1942). In the first case we are concerned vith the evaluation of the phenomeiion of dark adaptation itself, in the second wvith the Linlimited number of special tests which canl be elaborated in respect of partictialr visuLal tasks, e.g. night ilying. Night visual capacity mav be described as the individUal response resulting from all the factors concerned in the particular task, visual, adaptive, psychological and training; in other words, the reactions of the subject as a wvhole. Good dark adaptation is an obviouls requirement for a high standard of night vistLial capacity, but no other correlation exists.It follows that an instrumenit designed to test dark adaptationi is ideallv one wvhich, when used to evaluate this pirocess, does not cvaluate anything else, and a patch of light, sUitably controlled, is, in theorv, the most suitable means for testing dark adaptation.There are, how,ever, a nuMber of coniplicating factors. For example, as is well knowvn, different areas of, the peripheral retina of the dark-adapted eve are not equallv sensitive; the most sensitive area being an annnulus betwveen some 10°and 20°around the fovrea. This varying retinal sensitivitv has given rise to sharp differences in the methods of testing dark adaptation. Heclbt and Shlaer (1938), for example, insist on the necessity of testing a definitely loccated retinal area (obviouLslv reqUiring a fixation spot), vhereas many workers in this countrv Yudkin, Wilkinson, Pollak andl others-have tised a test object wxithoLlt a fixation spot. Since under the stimulus of light the eye automnatically tends t(o ulse the most sensitive part of the retina, a lack of uniform sensitivity does not necessarily require the testing of a definite retinal area.If a test object is uised, it shoLuld inmke the minimuim demands in regard to acuity, and its shape should...

show abstract

Dark-Adaptation and Psychology

Cited by 2 publications

References 0 publications

European Conference of the Nutrition Society

European Conference of the Nutrition Society

An Instrument for Testing Dark Adaptation

Contact Info

Product

Resources

About