Background: The number of elderly drivers is increasing. The primary purpose of public policy requiring vision screening for driver's license renewal is to identify, and, when necessary, restrict drivers with functional vision impairments. Because of age-related ocular conditions, elderly drivers, as a group, have a higher incidence and prevalence of functionally impaired vision. To date, there is no empirical evidence of a significant predictive relationship between changes in vision function and automobile crashes.
Methods: Most states require vision screening for driver's license renewal, whereas some do not. Among those states requiring vision screening, there is considerable variation in the frequency and level of testing. Efforts to determine the role of vision in driving, while suggestive, have not been useful in identifying at-risk older drivers.
Results: Researchers have observed that older drivers are often aware of their decreased functional capacity and voluntarily adjust their driving patterns by driving less frequently, for shorter distances, during daylight hours, more slowly, and during non-rush hours. However, although not statistically significant, the decline in the mean annual traffic fatality rates with increased state vision screening requirements suggests a possible beneficial effect of vision screening.
Conclusions: Because older drivers are at risk for sight-threatening conditions, they are most affected by vision screening requirements for driver's license renewal. Since a loss of driving privileges represents a major loss of mobility and independence, there is a pressing need to better understand the relationship between age-related vision changes and the frequency and severity of traffic crashes.