The object of this paper is to ask attention, briefly, to the physiologic results of regular use of the eyes in bright light, and more especially to raise the question as to whether progressive myopia in school children is not attributable to a large extent to such use. Also to propose a method of estimating the quantity of light in a given place or room with some approach, at least, to mathematical exactness.
The prevalence of myopia among school children attracted the notice of observers more than thirty years ago. Cohn examined the eyes of 10,000 school children and reported over 2 per cent. myopic in the elementary departments, over 10 per cent. myopic in the intermediate departments, more than 19 per cent. myopic in the high schools, and more than 26 per cent. myopic in the gymnasium. The showing discloses an almost regular ratio of increase from the lower