A new vision test may help predict which drivers can still sit safely behind the wheel and which ones should stop driving.
A study of nearly 300 people, ages 55 to 87, found that an experimental computer vision exam seems to be helpful in identifying drivers who are more likely to have traffic accidents.
The findings suggest "that there may be a way to protect older drivers and the community in a very reasonable way," said Jared B. Jobe, chief of the National Institute on Aging's adult psychological development branch, which sponsored the study.
Researchers at the University of Alabama in Birmingham used computer screens filled with visual distractions to gauge how well drivers could pick out cars, trucks and other objects scattered on the screen. Unlike standard vision tests, this test was designed to measure how well people were able to process what they saw--something that is key to safe driving.
People in the study were tracked from 1990 to 1993. The team of researchers, which was led by Cynthia Owsley with the clinical research unit at the Eye Foundation Hospital in Birmingham, also collected traffic-accident reports to identify crashes involving the drivers.
During the three-year follow-up period, 56 people in the study were involved in at least one traffic accident. The study found that people who showed a 40% or greater impairment in their "useful field of view" were twice as likely as others in the study to be involved in a traffic accident. The study also found that for every 10-point reduction in a driver's useful field of view, the risk of being in an accident rose 16%, regardless of the driver's age.