The Duke of Edinburgh is recovering after a car crash that left him “very shocked” and shaken but unhurt.
According to a witness, Philip, 97, told police he had been “dazzled by the sun”.
The glare of the low-lying sun can be a particular problem for drivers at certain times of year.
Twenty-five people were killed in crashes on Britain’s roads in 2017 when a driver dazzled by the sun was a contributory factor, according to Department for Transport data.
A further 3,146 were injured, including 484 who were seriously injured.
The AA and the Federation of Manufacturing Opticians say having the right pair of sunglasses can help prevent the potentially-fatal hazard.
A pair of everyday sunglasses might not be suitable for driving, so a pair of driving sunglasses should always be kept in a vehicle.
Motorists are recommended to have a thorough eye examination every two years to determine if prescription sunglasses are needed.
The onus is on the driver to have good vision, so failing to have eyesight corrected and protected from the sun could invalidate insurance in the event of a road accident.
Two women required hospital treatment after the crash involving the duke on the A149 near Sandringham in Norfolk on Thursday afternoon.
Witness Roy Warne, 75, told the Sun he heard Philip tell police he had been “dazzled by the sun”.