Fig. 4.

Simulated vision chart seen through the refractive statuses of − 3.00 D WTR and ATR simple myopic astigmatism (COAS vision simulation program). Without the slit, both groups could see best at 67 cm distance (at which the circle of least confusion coincides on the retina). With the slit, the distance at which the vertical focal lines lie on the retina showed better vision than before (6 m of the − 3.00 D WTR astigmatism and 33 cm of the − 3.00 D ATR astigmatism). Note that the vision at 33 cm is comparable to that at 67 cm of the − 1.50 D ATR astigmatism (Fig. 3)