MERIDIONAL ANISEIKONIA AT OBLIQUE AXES

Many patients experience difficulties in wearing astigmatic corrections. Primarily, asthenopic symptoms are reported, but annoying distortions of objects in space are also mentioned. As a rule, the spatial distortions disappear in a short time when the correction is worn constantly. The asthenopic symptoms, on the other hand, may persist and even be so severe as to force the patient to abandon the glasses altogether. This is particularly true when the axes of the required cylinders are oblique.The ocular discomfort has been attributed to the distortion of the retinal images produced by the cylindric spectacle lenses. These distortions have their principal effect in binocular vision. At an early date Wadsworth,1 Culbertson2 (who tried to correct the spatial distortion by rotating the cylinders) and Lippincott3 described some of the changes in the position and form of objects caused by astigmatic corrections. However, they did not explain the phenomena