Abstract
Purpose:
All states require drivers to pass a vision test before licensure and the most common restriction placed on a driver’s license requires the driver to wear corrective lenses while driving. Vision testing parameters and requirements vary widely from state to state. To date, there have been no published reports that link stringency of vision testing standards to a reduction in Motor Vehicle Crash (MVC) fatalities. The purpose of this study is to determine whether stringency of vision testing for licensure has an effect on MVC fatalities.
Methods:
The most recent data on traffic fatalities by state, published in 2011, was obtained from the National Highway Safety Administration Fatality Analysis Reporting System. The unique state vision laws were collected from the AAA Motor Laws website and the Summary of Medical Advisory Board Practices website. The relationship between stringency of vision requirements (visual acuity (VA) expressed in logMAR units, visual fields, and allowance of bioptic telescopes) and MVC fatalities was evaluated using an Analysis of Variance (ANOVA) test and regression analysis.
Results:
The regression analysis yielded a low p-value (0.00028) which leads to the conclusion that there is a significant difference between VA requirements and MVC fatalities. On average, states with more stringent VA requirements experienced fewer MVC related fatalities. There was no significant difference in MVC fatalities between states with visual field (VF) requirements and those without VF requirements. Additionally, among states with VF requirements, states requiring a wider VF did not appear to fare better than those with narrower VF requirements. Results also indicated that the use of bioptic telescopes was associated with higher MVC fatalities, particularly among the elderly.
Conclusions:
This is the first study of its kind to substantiate the notion that vision laws do, in fact, have an effect on traffic fatalities. Most of the findings support stringency of vision laws as a means of improving road safety for drivers and pedestrians alike. Future prospective studies should aim to establish federally standardized vision testing that would effectively eliminate inconsistencies between states.
Keywords: 754 visual acuity