Effect of aging on the monochromatic aberrations of the human eye

We measured the contrast sensitivity (CS) of a group of older subjects thro ugh natural pupils and compared the results with those from a group of youn ger subjects. We also measured each subject's monochromatic ocular wave-fro nt aberrations using a crossed-cylinder aberroscope and calculated their mo dulation transfer functions (MTF's) and root-mean-squared (RMS) ware-front aberrations for fixed pupil diameters of 4 mm and 6 mm and for a natural pu pil diameter. The CS at a natural pupil diameter and the MTF computed for a fixed pupil diameter were found to be significantly poorer for the older g roup than for the younger group. However, the older group showed very simil ar MTF's and significantly smaller RMS wave-front aberrations compared with the younger group at their natural pupil diameters, owing to the effects o f age-related miosis. These results suggest that although monochromatic ocu lar wave-front aberrations for a given pupil size increase with age, the re duction in CS with age is not due to this increase. (C) 1999 Optical Societ y of America [S0740-3232(99)02509-0]. OCIS codes: 080.1010, 170.4460, 330.4 300, 330.4460.