Effect of Ephedrine on Dark Vision

Abstract

THE effect of drugs on night vision and dark adaptation is a problem of both theoretical and practical importance which has already received a good deal of attention, particularly during the Second World War. Of the various drugs the effects of which have been investigated systematically, ephedrine has apparently featured in only one experiment, namely, that of Rose and Schmidt¹. These authors report no significant effect on dark adaptation. Further studies on the influence of ephedrine and other sympathicomimetic drugs are particularly desirable in view of the claims of Babskiľ², Kekcheyev³ and their associates that the sympathetic nervous system exerts an ‘adaptive influence’ on the visual analyser, and of recent research at the Institute of Psychiatry which suggests that the impaired dark vision of neurotic patients may be due to sympathetic over-activity. To obtain further information on this point, an experiment was undertaken with four subjects using a test of night visual ability which had previously been shown in several studies to differentiate normal from neurotic groups.