Researchers from the University of Western Australia have examined at what point declining vision increases the risk of a car accident.
The researchers evaluated 29 years of data from 31,000 drivers in Western Australia, aged over 50 years, comparing ophthalmic information with police-reported crash, licensing and hospital morbidity data.
More than half of the 4,000 older drivers involved in a car crash, accounting for 14 per cent of older drivers in Western Australia, were found to be experiencing some degree of visual field loss.
Visual field loss of any sort in both eyes increased the odds of a car crash by 84 percent; moderate visual field loss in one eye increased car crash risk only if it occurred in the left upper or lower quadrants.
Severe vision loss in any quadrant increased the chances of an accident, while central vision loss in either eye was not associated with an increase in car crash incident.
‘We hope to better inform clinicians, licensing authorities, and people with visual field defects of the thresholds for visual field loss that still allows for safe driving,’ said Siobhan Manners, lead researcher from the University of Western Australia.
Findings from the study were presented this month at the 127th annual meeting of the American Academy of Ophthalmology (November 3-6) in San Francisco.