Every one is familiar with the use of the stereoscope for developing binocular vision, fusion amplitude, stereopsis and duction power. It is my purpose in this discussion to present an additional use of the stereoscope unconnected with any of the aforementioned uses. To understand the bearing of this application of the stereoscope, it is necessary to consider a brief preliminary discussion on some of the causes of discomfort incident to the first wearing of correcting lenses.
Of the several causes responsible, unquestionably one important cause is the fact that the lenses tend to break up old established ocular habits. The person with hyperopia who is given his first plus correction had for a time previous to his correction established ocular habits which served his needs even though under strain. In uncomplicated cases, he had developed a habit of forcing his accommodation ahead of his convergence. If the