Driving with sunglasses – what are the rules?

Glare from a bright summer sun can be dangerous for drivers and other road users. That is why it is important to stay safe by wearing the correct type of sunglasses.

To help you make the most informed decision when it comes to choosing the right type of sunglasses, we have created this legal guide to explain the law and how different types of sunglasses work.

Is it illegal to wear sunglasses when driving?

In most cases, it is not illegal to wear sunglasses when driving a vehicle in the UK.

All sunglasses are rated in categories from 0 to 4. If your sunglasses are in category 0, 1, 2 or 3 then you are safe and legal. However, if you wear sunglasses that are in category 4 then you will be breaking the law.

Category 4 sunglasses are very dark and only let in a very small percentage of daylight. As a result, they can impair your vision when behind the wheel.

Also, some tinted glasses may be unsuitable for driving as they can make it difficult to see in low light situations.

In summary, while wearing sunglasses is not prohibited, drivers must ensure that their vision remains unimpaired and that they can drive safely under all conditions. Failure to do so could result in legal consequences under the Road Traffic Act 1988 or other applicable laws.

What does the law say?

Under Section 96 of the Road Traffic Act 1988, it is an offence to drive if your eyesight falls below the required legal standard.

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.

What does the Highway Code say?

It isn’t automatically unlawful to wear sunglasses while driving in England and Wales. What matters is whether the eyewear interferes with your ability to see clearly or operate the vehicle safely.

Both the Highway Code and wider legislation require drivers to maintain unobstructed vision at all times.

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

Dangerous driving

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.

Dangerous driving covers behaviour that falls far below the standard expected of a competent motorist and includes actions that create a clear risk to others.

Avoidable distraction or impaired vision caused by overly dark sunglasses could contribute to such a finding.

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Sunglass categories

There are two essential requirements in lenses used for driving:

1. Vision must remain clear and the sunglass shape must not hinder peripheral vision.
2. Sufficient light must be to let through for you to you see properly. This will depend on the circumstance you are in when behind the wheel.

Whenever you purchase sunglasses, you will be able to see what category your pair are, and if they are suitable to be used when driving.

This can be found on the label on the packaging, or if it comes with a prescription card. If you are in a store, then it will also be found on a swing tag.

Each category is broken down by the level of VLT – visible light transmission.

VLT is the percentage of visible light that passes through a sunglass lens and reaches the eye. The lower the VLT, the darker the lens and the less light it allows through.

Here is a breakdown of what each category means for sunglasses, and whether it is legal or suitable to drive a vehicle in the UK:

Category 0

Category 0 have either clear lenses or a very light tint, allowing 80 to 100% of light to pass through. They are legal for driving and are generally suitable in low-light conditions, overcast weather and at night because they do not significantly reduce visibility. However, they provide little protection against bright sunlight or glare.

Category 1

Sunglasses in category 1 allow 43 to 80% of VLT through and are designed for low levels of sunlight. They are legal for driving during the day, but they are not recommended for night driving because the tint can reduce visibility when light levels are already low. They offer modest glare reduction while maintaining good daytime vision.

Category 2

Sunglasses in category 2 are VLT of 18 to 43% and are the most common type of everyday sunglasses. They are legal for driving and are widely regarded as one of the best options for daytime use, providing a good balance between glare protection and visibility. However, they should not be worn at night or in other low-light conditions.

Category 3

Category 3 allow 8 to18% of VLT, these sunglasses are intended to be used for bright sunlight, such as during summer driving or at the beach – or situations where sudden glare can be an issue (e.g. bright sunshine following rain). They are legal for driving in daylight and provide strong protection against glare. However, they are too dark for night-time use and should be removed when visibility begins to deteriorate.

Category 4

Category 4 sunglasses are the darkest type of sunglasses you can buy and only let 3-8% of light to pass through. They are designed for extremely bright conditions, such as high-altitude mountain environments or glaciers. They are not suitable for driving and should be labelled as such. Because they significantly reduce the amount of light reaching the eyes, they are unsafe for road use.

Sunglass categories table

If you are caught by the police for dangerous driving, the type of sunglasses you are wearing could be a factor.

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Dangers of driving in bright sunshine

Here are some of the main challenges of driving in bright sunshine. This can happen year-round, so make sure you have made the necessary precautions to minimise the dangers:

• Glare and dazzle can temporarily reduce or completely obscure a driver's vision, making it difficult to see the road, other vehicles, pedestrians, cyclists and other hazards
• Reduced reaction times can occur when drivers are dazzled by bright sunlight, increasing the risk of incidents and collisions
• Difficulty seeing traffic lights, road signs and lane markings can make it harder to drive safely and follow the rules of the road
• Reflections from wet roads, puddles, snow, vehicle bodywork, and windscreens can intensify glare and further impair visibility
• Eye strain and fatigue can develop during prolonged exposure to bright sunlight, potentially affecting concentration and driving performance, especially during lengthy summer road trips
• Pedestrians, cyclists, animals, and stationary vehicles (or anything else) may be harder to spot when sunlight shines directly into a driver's eyes
• The risk is particularly high during sunrise and sunset, when the sun sits lower in the sky and is more likely to shine directly through the windscreen
• Momentary blindness can occur when moving suddenly between shaded areas and bright sunlight, preventing the eyes from adjusting quickly enough

Best sunglasses for driving

Category 3 sunglasses are the best option for daytime driving, as they offer perfect sun protection, but are not considered too dark to risk the safety of the driver and other road users.