Don’t be in the dark when it comes to driving in sunglasses, warns the RAC

Motorists who wear sunglasses that are too dark are being warned that they could be breaking the law. The warning comes as the UK faces its fourth summer heatwave.

While having a good pair of sunglasses to wear while driving is essential to staying safe with the sun so fierce, sunglasses rated at the highest level on the Visible Light Transmission scale can actually impair vision while driving.

This refers to shades in ‘category four’ which only let in a very small percentage of daylight. The category can be found on the label of the packaging.

Additionally, some tinted glasses may be unsuitable for driving as they can make it difficult to see in low light situations – which drivers could experience, for instance, during an unexpected thunderstorm when the light level drops dramatically.

Under Section 96 of the Road Traffic Act 1988, it is an offence to drive if your eyesight falls below the required legal standard, which could result in a fine and three penalty points.

This applies to any situation where your vision is compromised, which includes wearing overly dark sunglasses that make it difficult to see clearly and meet the necessary eyesight rules.

Rule 94 of the Highway Code also advises against using tinted glasses, lenses, or visors at night or in conditions of poor visibility if they limit how well you can see.

Furthermore, if wearing sunglasses reduces a driver’s ability to spot hazards or other road users, it could amount to careless or even dangerous driving in more serious cases.

Category three sunglasses are the best option for daytime driving, as they offer sun protection, but are not too dark to risk the safety of the driver and other road users.

Category two, although not as dark, are also considered a good option for daytime driving, providing a good balance between glare protection and visibility. However, they should not be worn at night or in other low-light conditions.

Category one sunglasses are designed for low levels of sunlight. While they are legal for driving during the day, they only offer modest glare reduction.

RAC policy officer Harriet Hernando said: “Most of us will be reaching for our sunglasses this week, but many will not realise that the darkest of shades could be unsuitable for driving, and even illegal in the case of category four sunglasses.

“We urge drivers to check their sunglasses, especially if they are normally used for extremely bright conditions, such as high-altitude mountain environments. These will be unsafe for driving, could impair your vision and even lead to a fine and penalty points.”