While continuing the work on the light minimum, we investigated the ability of the eye to detect a difference in the degree of brightness, to discover whether this might be significant as a diagnostic sign in early glaucoma. If such a test proved to be of value, it might serve as an adjunct to, or a substitute for, the light minimum test which requires a prolonged stay in the dark room and a number of readings during the course of dark adaptation.
REVIEW OF THE LITERATURE
An earlier article1 gave a brief summary of work previously done on the light sense which seemed particularly relevant to our line of investigation. In the past few years, more work has been done which should be mentioned here. This review of the literature, like the previous one, discloses many interesting points on different phases of the light sense ; however, we have
DERBY GS, CHANDLER PA, O'BRIEN ME. THE LIGHT SENSE IN EARLY GLAUCOMATHE SMALLEST DIFFERENCE IN BRIGHTNESS PERCEPTIBLE TO THE LIGHT ADAPTED EYE (LIGHT DIFFERENCE). Arch Ophthalmol. 1929;1(6):692–703. doi:10.1001/archopht.1929.00810010718004