Hyderabad: Over half of the Indian drivers responsible for road accidents have at least one vision disability, according to a study by the Indian Institute of Science (IISc).
Analyzing how a driver’s vision impacts road safety, the study found that the chances of crashing were 81% higher in drivers with visual disability.
“Statistics indicate that 250-300 people die daily in road crashes in India and the country ranks lowest in terms of road safety. There is a need to scientifically analyse the factors causing road accidents and come up with guidelines to take corrective actions,” said Ashish Verma, professor at the civil engineering department, IISc, who carried out the study to analyse how drivers’ vision influences road safety.
The study was conducted by carrying out tests on 387 professional drivers from Karnataka Road Transport Corporation, Bangalore Metropolitan Transport Corporation, and Vijayanand Road Lines and volunteers from IISc.
The study was based on public reports that driver error is the cause of road accidents in 78% of the cases.
Typically, any person can give a self declaration about his or her medical fitness to qualify for a license test in India, and vision acuity is tested only on drivers of commercial vehicles.
The tests in the study were conducted to assess colour vision, binocular vision, depth perception, contrast sensitivity, glare recovery, horizontal field vision and vertical field vision.
Depth perception of the speed and distance of the vehicle coming from the opposite direction determines a driver’s judgment while overtaking vehicles on a road with a divider. Contrast sensitivity is able to identify an object from its background. Horizontal and vertical peripheral vision assesses the ability to sense movement on the sides, above and below, while looking forward.
“Glare is the sensation caused when bright light is flashed in front of the eyes and vision is obstructed for a couple of seconds. Recovery from glare is important during night driving as oncoming vehicles use high beam. Glare increases reaction time in drivers, compromising safety,” said the study.
The study, which was first published in Current Science, said that even as people with no visual disabilities were involved in road crashes, the test results showed a significant relation between road crash tendencies of drivers and visual defects.
“Strict visual screening before issuing a driving licence can help create safe drivers and crash-free roads,” said Verma.