Effects of ocular dominance on contrast sensitivity in middle-aged people.

Purpose. Our aim was to compare contrast sensitivity values of the dominant and nondominant eyes of healthy middle-aged subjects. Material and Methods. Ninety eyes of 45 healthy middle-aged subjects (30 males and 15 females) were included in this study. Patients were aged between 40 and 60 years, having uncorrected visual acuity (UCVA) of 20/25 or better (Snellen chart). Ocular dominance was determined by hole-in-the-card test. Functional acuity contrast testing (F.A.C.T.) was measured using the Optec 6500 vision testing system (Stereo Optical Co. Inc., Chicago, IL, USA) under both photopic and mesopic conditions. Results. At all spatial frequencies (1.5, 3, 6, 12, and 18 cpd), under mesopic conditions, the contrast sensitivity values of the dominant eyes were slightly greater than those of the nondominant eyes; but only 18 cpd spatial frequency measurements' difference was statistically significant (P = 0.035). Under photopic conditions, the contrast sensitivity values of the dominant eyes and non-dominant eyes were similar at all spatial frequencies (P > 0.05). Conclusions. The photopic and mesopic contrast sensitivity values of dominant and nondominant eyes of healthy middle-aged people were similar at all spatial frequencies, except at mesopic 18 cpd spatial frequency.