ABSTRACT
Twelve normal subjects and 8 patients were examined with the New Aniseikonia Test (NAT) and the Hess chart. In the normal subjects, aniseikonia was produced by mounting an iseikonic lens in front of one eye, which optically enlarges the image of an object by 20%. The aniseikonia produced ranged from 10 to 21% (mean=16%) by the NAT. On the Hess chart, all of these subject demonstrated similar patterns to patients with slightly defective adduction of both eyes. Their aniseikonia ranged from 16 to 33 % (mean=26 % vertically and 24 % horizontally: square shaped ). In the 8 patients, the NAT measured aniseikonia from 6 to 24% (upper limit of NAT) and Hess chart measured aniseikonia from 0 (estimated normal) to 65 %. The 2 cases with aniseikonia more than 50% on the Hess chart were cases of unilateral aphakia corrected with glasses. We believe these results are due to rotational magnification of the strong convex lens. In Hess chart examination, the effect of aniseikonia and effect of the correction lens should be taken into account.
