VISION AND DRIVING IN THE ELDERLY

Background. This is an overview of a program of research to identify v isual and cognitive factors which place older drivers at risk for vehi cle crashes. Methods A sample of 294 older drivers participated in a p rotocol which assessed eye health, visual sensory function (i.e., acui ty, contrast sensitivity, peripheral field sensitivity), the size of t he useful field of view (UFOV), and cognitive status. The sample was a ge-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 th e number of at-fault crashes incurred during the 5-year period before our protocol test date (retrospective study) and during the 3-year per iod after our test date (prospective study). Results. Older drivers wi th visual sensory impairment, cognitive impairment, and/or a constrict ion in the size of the useful field of view were at greater risk for c rashes than were those without these problems. The UFOV test had bette r sensitivity and specificity than visual sensory or mental status tes ts in identifying those older drivers at risk for crashes. Conclusions . The UFOV test's superior preditability is most likely due to its rel iance on both visual sensory abilities and higher order attentional sk ills. This study suggests that interventions which reduce either visua l sensory or attentional impairment may also reduce accident risk in o lder drivers, an issue we are currently investigating.