2010 Volume 31 Issue 4 Pages 134-139
Purpose: We investigated the effect of astigmatism and pupil size on visual function.
Methods: Included in this study were 11 eyes of 11 normal subjects. We used a modified CAT-2000 (Menicon, Aichi), with an electronic pupillometer built into the contrast visual acuity measuring device. Because control of pupil size was not possible, we used artificial pupils. Visual acuity with artificial pupil (2.0～5.0 mm, 0.5 mm step) and astigmatism (0～3.0 D, 0.5 D step) after cyclopentolate (Cyplegin®) instillation were measured by 100% contrast photopic vision.
Results: Visual acuity decreased significantly, pupil size becoming large at astigmatism over 1.0 D. Visual acuity decreased as astigmatism and pupil increased.
Conclusions: This study suggests that in the astigmatic eye, dilated pupil size diminishes retinal image quality by enlarging the circle of least confusion, affecting visual function.
