ARE YOUR SUNGLASSES BREAKING THE LAW? Drivers warned over illegal sunglasses as fourth UK heatwave raises RAC road safety concerns
- Perry Richardson
- 8 hours ago
- 2 min read
As the UK experiences its fourth heatwave of the summer, motorists are being reminded that not all sunglasses are suitable for use behind the wheel. Road safety experts have warned that wearing lenses that are too dark could impair a driver’s vision, potentially leading to prosecution if their eyesight falls below the legal standard.
While sunglasses are an important tool for reducing glare and improving comfort in bright sunshine, drivers should pay close attention to the Visible Light Transmission (VLT) category shown on the product packaging. The warning centres on category four sunglasses, which allow only a very small amount of visible light to pass through the lenses.
Category four sunglasses are typically designed for extreme environments such as high-altitude mountain conditions or glaciers, where sunlight is exceptionally intense. Because they significantly reduce the amount of light reaching the eyes, they are considered unsuitable for driving and can make it difficult for motorists to react safely to changing road conditions.
The issue becomes particularly relevant when weather conditions change unexpectedly. Although drivers may begin a journey in bright sunshine, heavy cloud cover or thunderstorms can rapidly reduce visibility. Wearing heavily tinted lenses in these conditions can make it harder to detect hazards, pedestrians, cyclists and other road users.
Under Section 96 of the Road Traffic Act 1988, it is an offence to drive if a person’s eyesight does not meet the required legal standard. That requirement applies regardless of the reason vision is impaired, including wearing sunglasses that are too dark to allow safe driving. Offenders could face a fine and three penalty points if their vision falls below the required standard.
The Highway Code also provides guidance on the issue. Rule 94 advises drivers not to wear tinted glasses, lenses or visors at night or in poor visibility if they restrict vision. If investigators determine that dark sunglasses contributed to a driver’s inability to identify hazards, the circumstances could also lead to allegations of careless driving or, in more serious cases, dangerous driving.
For most daytime journeys, category three sunglasses are regarded as the safest choice. They provide strong protection against bright sunlight and glare without excessively reducing visibility. Category two lenses are also considered suitable for daytime driving, offering a balance between glare reduction and clear vision, although they should not be worn in darkness or low-light conditions. Category one sunglasses provide only limited glare protection but remain legal for daytime driving.
Harriet Hernando, RAC policy officer, 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.”
