Visual acuity and highway accidents

An analysis of binocularly obtained visual acuity test scores of 13,786 automobile drivers was made in terms of the number of accidents reported by each driver during a 12 month period. For each of eight different age categories the drivers were classified as having poor acuity if their scores were below the lower quartile, and as having good acuity if their scores were above the median. The percent of drivers with poor acuity who reported three or more accidents was approximately double the percent of drivers with good acuity who reported three or more accidents. The proportion with poor acuity who reported two accidents was approximately 50% greater than the proportion for those with good acuity. These differences were statistically significant and prevailed at all age levels above 19 years. The differences in proportions reporting one accident and no accident for the poor and good acuity categories were not significant.