[Stereoscopic vision in reduced visual acuity].

Like other authors, we observed a number of cases with relatively good stereoscopic acuity despite poor visual acuity among patients with primary microstrabism. In order to analyze this observation experimentally the patients' visual acuity was reduced monocularly and binocularly, by means of semitransparent membranes of increasing density, to 0.3 and 0.1, and stereoscopic visual acuity was then examined using the Titmus and TNO tests. Both tests showed that in most cases stereoscopic vision was only moderately reduced, and in some cases not at all.