As the weather finally begins to improve drivers are being urged by road safety experts to make sure they don’t fall foul of a little-known driving rule.
This week is Sun Awareness Week and while there’s plenty of advice being offered on the potential health effects of overexposure, road safety charity IAM Roadsmart is also offering words of caution on staying safe on the road.
While sunglasses are a must for motorists to avoid being dazzled, IAM Roadsmart’s Tim Shallcross warns that not all glasses are suitable for drivers and those who buy their shades online should be particularly cautious.
The EU has set standards for elements of sunglasses such as frame strength, shatter resistance and UV protection but it also has four grades for the level on tint in lenses.
While the three lower grades are all suitable for driving in daylight, category four lenses are so dark that the standards state they are not suitable for driving or road use at any time.
Failing to heed this warning could be seen as careless driving, which carries an on-the-spot fine of £100.
Tim Shallcross explains: “The darkest is category four, which lets just three per cent to eight per cent of the light through. These are very dark, like ski goggles. They are so dark that they should not be used for driving at any time, and category four sunglasses must be labelled as unsuitable for driving.”
Where to find the rating
Most sunglasses on sale in shops will be have the category clearly labelled, usually on the arm, but Tim Shallcross warns that those bought online aren’t always so clear.
He says: “A look through several shopping websites revealed that very few sellers display the tint category or any symbol, so you have no way of telling whether the glasses are suitable for driving until they arrive.
“A few are advertised as category 4 and suggested as being good for cyclists, although the official standard states they are ‘not suitable for driving and road use’, and common sense would say that if they’re too dark for driving, they’re too dark for cycling.
Photochromic glasses, which lighten and darken depending on the ambient light, aren’t marked but they should be fine for most cars because they respond to ultraviolet light, which car windows block.