Validity of vision screenings at driver's license renewals

Background: An analysis of data collected from state department of transportation websites was utilized to analyze whether or not states with frequent vision screenings required for those over 65 see lower accident rates than states that do not screen for vision at any license renewal. Literature was reviewed to discuss the implications vision has on driving and other possible options for licensure vision testing. Methods: Data was collected via an internet search using department of transportation data and national highway traffic safety administration data from 2015. The information that was collected included accident rates in the population 65 and older. This data was analyzed by placing states in one of two groups: states that do not require vision screening at renewal and states that require a vision screening at renewal every 5 years or less. Results: By running an unpaired t-test, no statistically significant difference was found between the two testing groups (no vision screening required and vision screening required within 5 years). Conclusions: Visual acuity and visual field testing that is currently used widely by state department of motor vehicle offices does not appear helpful for reducing accident rates in drivers over 65 years old. There are many other options for assessing driver safety such as useful field of view, contrast sensitivity, and driving simulations that should be considered.