VISUAL-ACUITY CHANGES THROUGHOUT ADULTHOOD IN NORMAL, HEALTHY EYES - SEEING BEYOND 6 6/

There are many useful longitudinal and cross-sectional epidemiological studies of how visual acuity (VA) deteriorates with age. However, few studies have evaluated age-related VA changes in normal, healthy eyes . Data from three previous studies that included VA measurements taken with logMAR charts from subjects with normal, healthy eyes were colla ted and additional data from 42 subjects were added. This provided VA results from 223 subjects (age range 18 to 80 years). Mean logMAR VA i mproved from -0.13 (Snellen equivalent 6/4.5) in 18- to 24-year-olds t o -0.16 (Snellen 6/4(-1) in 25- to 29-year-olds and then gradually bec ame worse with age to a mean value of -0.02 (Snellen 6/6(+1)) for subj ects over 75 years of age. The inadequacy of 6/6 as a norm value of VA is illustrated. The data show VA levels far superior to the data from the standard references of Pitts (1982) and Weale. (1975, 82) We sugg est that this is because we used logMAR charts (providing nontruncated data), the subject's optimal refractive correction (rather than habit ual) and strict exclusion criteria ensuring that only subjects with no rmal, healthy eyes were recruited for the studies.