Suppression Versus Amblyopia

Abstract

When I began to consider this subject I decided that comparing suppression with amblyopia ex anopsia would be like comparing a cat with a tiger, both belong to the same family and spring from the same source, yet are unlike in their habits and temperaments and must be handled with a different approach. generally accepted definition of suppression (as I understand it) is the temporary suspension of seeing in an eye which ordinarily has good vision. understanding which I have of amblyopia ex anopsia is a habitual suspension of vision which has become constant and thus caused poor visual acuity. re­ sult in each instance is from a similar cause, the incoordination of the two eyes which, without the suspension of vision, would be sufficient to result in diplopia. To avoid the annoying diplopia the brain unconsciously brings about suppression, which if it is constant for any length of time becomes amblyopia ex anopsia. As Dr. H. M. Burian stated in his paper on Fusional movements in permanent stra­ bismus (Arch, of Ophth., Oct., 1941), The urge to avoid disturbing double vi­ sion is strong. It is not necessarily a conscious effort. It is present even in small children, and suppression as well as amblyopia is caused by it. A good ex­ ample of suppression in normal eyes is one's ability to use the ophthalmoscope or microscope without closing the second eye. One learns to ignore the image of the eye which is not using the instrument, a temporary monocular suppression. eyes and brain do the same thing in squint as a protective mechanism against what