This article is only available in the PDF format. Download the PDF to view the article, as well as its associated figures and tables.
A review of the literature reveals that for many years visual acuity of 6/15 or 6/12 in both eyes has generally been accepted as a minimal requirement for orthoptic training. In view of recent developments in orthoptic methods and also because maximal visual acuity of 6/15 or less in one eye is common with neglected concomitant strabismus, reconsideration of the minimal visual acuity requirement is indicated.
Visual acuity of 6/15 or better is dependent on foveal function; however, persons with small central scotomas frequently have single binocular vision. Also it is generally accepted that the peripheral fields of vision play a predominant role in fusional movements. For these reasons no one doubts that singular binocular vision may exist without foveal function in one or both eyes. Rather, the premise that visual acuity of 6/15 or better is necessary for orthoptics seems based on the belief that foveal fixation is essential
SWAN KC, LAUGHLIN E. BINOCULAR ORTHOPTIC TRAINING FOR AMBLYOPIC PATIENTS. Arch Ophthalmol. 1944;32(4):302–303. doi:10.1001/archopht.1944.00890100060008
Coronavirus Resource Center
Customize your JAMA Network experience by selecting one or more topics from the list below.