VISION AND DRIVING IN THE ELDERLY

Background. This is an overview of a program of research to identify visual and cognitive factors which place older drivers at risk for vehicle crashes. Methods A sample of 294 older drivers participated in a protocol which assessed eye health, visual sensory function (i.e., acuity, contrast sensitivity, peripheral field sensitivity), the size of the useful field of view (UFOV), and cognitive status. The sample was age-and crash-stratified to ensure inclusion of older adults covering a wide range of ages (55 to 90 years) and crash frequencies during the previous 5 years (0 to 4 crashes). The major dependent variable was the number of at-fault crashes incurred during the 5-year period before our protocol test date (retrospective study) and during the 3-year period after our test date (prospective study). Results. Older drivers with visual sensory impairment, cognitive impairment, and/or a constriction in the size of the useful field of view were at greater risk for crashes than were those without these problems. The UFOV test had better sensitivity and specificity than visual sensory or mental status tests in identifying those older drivers at risk for crashes. Conclusions. The UFOV test's superior preditability is most likely due to its reliance on both visual sensory abilities and higher order attentional skills. This study suggests that interventions which reduce either visual sensory or attentional impairment may also reduce accident risk in older drivers, an issue we are currently investigating.