Comparing Square Wave Grating Acuity Testing To Snellen Acuity Testing In Non-Presbyopic Adults.

We compared monocular unaided acuities of non-prebyopic adults, utilizing square wave gratings and Snellen at both distance and near. The acuity correlated well at distance (.86 correlation coefficiency) with the exception of the highly myopic eyes. However, the T-value (10.42) indicates the acuities are significantly different, especially with the highly myopic eyes. At near, using the Teller Acuity Cards, the correlation on coefficient was just below the acceptable level. The T-value (5.76) for near also indicates the acuities were dissimilar between these two testing methods. This variability of measured acuities may be due to the 'edge artifact' of the square wave gratings and the several differences between the two different types of testing methods.