Researchers investigate types of visual field loss linked to collision risk

University of Western Australia researchers examine link between visual field loss and vehicle collision risk

A man in a checked shirt is driving a car. On his left hand, which rests on the top of the steering wheel, the man wears a watch. The surroundings appear blurred outside the window of the car.

Researchers from the University of Western Australia have outlined a study on the link between reduced vision and collision risk at the annual meeting of the American Academy of Ophthalmology (3-6 November, San Francisco).

Scientists examined data from more than 31,000 drivers in Western Australia aged 50 and older.

During a 29-year period, 4000 people within the study group were involved in at least one car crash.

More than half of those who experienced a collision had some form of vision loss.

The researchers outlined how the area of vision affected, and the extent of visual loss, was strongly linked with crash risk.

Visual field loss of any kind in both eyes increased the risk of a collision by 84%.

Moderate visual field loss in one eye increased car crash risk only if it occurred in the left upper or lower quadrants. In contrast, severe vision loss in any quadrant increased the chances of a crash.

Central vision loss is either eye was not connected to an elevated collision risk.

Dr Siobhan Manners, of the University of Western Australia, highlighted that many people believe only good visual acuity or clarity of vision is necessary to be safe while driving.

“We hope these results will help educate the public about the importance of having an adequate field of vision to be able to continue driving safely. We also 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,” she said.