Monochromatic aberrations and myopia.

The monochromatic aberrations present in the eyes of a group of 21 young myopic subjects and 16 young emmetropic subjects were measured along the visual axis at three levels of accommodation. The aberrations were measured using a modified aberroscope technique which makes use of a retinal camera to photograph the shadow image of the aberroscope grid on the retina, while accommodation levels of 0, 1.5 and 3.0 D were induced consensually. Fourth-order aberrations were significantly different between the emmetropic and myopic groups, with the myopes showing lower fourth-order terms. A high proportion of the aberroscope grids photographed in the myopic eyes were too highly aberrated to permit analysis.