AMBLYOPIA is a frequent, yet little understood, visual defect. This fact was established by Downing,1 who in 1945 reported on ocular defects in 60,000 selectees for the United States Army. Among these he found 1,920 cases of uniocular amblyopia of unknown origin, a proportion of 1: 30. Does fixation in these instances remain centered on the fovea of the affected eye? This is the question under consideration.
The true nature of amblyopia has by no means been established. Harms,2 in 1938, demonstrated a relative lowering of the pupillary responses to light in amblyopic eyes. He was of the opinion that, in some manner, there occurs a suppression of the activity of the retina. On the other hand, Wald and Burian,3 Dyer and Bierman,4 and many others have stated the belief that amblyopia is due mainly to cortical suppression and that no physiological changes occur.