
Sunglasses are often chosen for how they look, but they play a much more important role in protecting your eyes. The right pair can help keep your vision comfortable in bright conditions while shielding your eyes from harmful ultraviolet (UV) rays.
Understanding what to look for, including terms like UV400 protection, can help you choose sunglasses t h a t not only suit your style, but also support your long‑term eye health.
What is UV light and how can it affect your eyes?
Sunlight contains ultraviolet (UV) rays, which are invisible but can have a lasting impact on your eyes. The two main types that reach us are UVA and UVB.
- UVA rays are present all year round and can contribute to long-term eye conditions such as cataracts and macular degeneration.
- UVB rays are more intense and can damage the surface of the eye.
While many people are aware of how UV affects the skin, fewer realise how sensitive the eyes are to UV exposure. Over time, repeated exposure without proper protection can increase the risk of eye health concerns.
Why UV protection in sunglasses matters
Sunglasses are not just about reducing brightness. A dark lens may feel more comfortable in the sun, but without proper UV protection, it may not be protecting your eyes at all.
In fact, darker lenses without UV protection can sometimes do more harm than good, as your pupils naturally widen in darker conditions, potentially allowing more harmful UV rays to enter the eye.
Choosing sunglasses with reliable UV protection ensures your eyes are properly shielded while you enjoy clearer, more comfortable vision outdoors.
For everyday comfort, this is often combined with lens options such as tinted lenses, photochromic or polarised lenses.
Learn the differences between tinted, polarised and photochromic lenses.
What does UV400 mean?

When you see UV400 protection on sunglasses, it means the lenses block 99–100% of harmful UVA and UVB rays. This is considered one of the highest levels of protection available.
UV400 refers to the wavelength of light that is blocked, covering the full range of ultraviolet radiation that can reach the eye.
Sunglasses with UV400 protection are a strong choice if you:
- Spend time outdoors
- Drive regularly
- Are exposed to bright or reflective environments such as water or snow
If you are frequently outdoors, you may also benefit from polarised lenses which reduce glare in high-reflection environments.
How to choose sunglasses with the right protection
When choosing sunglasses, it is important to look beyond the style and check that they offer the level of protection your eyes need.
Look for sunglasses that:
- Carry the CE mark
- Or meet British Standard BS EN ISO 12312-1
These indicators prove that the sunglasses meet safety requirements for UV protection. If you are looking for a higher level of protection, choosing lenses with UV400 protection can offer additional reassurance.
It is also important to remember that lens colour or darkness does not determine UV protection.
How UV protection works alongside lens types
UV protection is just one part of choosing the right sunglasses. Different lens types can enhance comfort depending on how you use your vision:
- Tinted lenses help reduce overall brightness and improve comfort in everyday environments
- Polarised lenses reduce glare from reflective surfaces, making them ideal for driving
- Photochromic lenses adapt automatically to changing light, offering convenience throughout the day
Explore our full guide to understand the difference between these lenses.
When should you wear sunglasses?

It is easy to think of sunglasses as something you only need on bright summer days, but UV rays are present throughout the year, even when it is cloudy.
Whenever you are outdoors during daylight, your eyes are exposed to UV. Levels tend to increase as the sun rises, peak when it is highest in the sky, and gradually reduce towards the evening, but exposure is still present throughout the day.
Wearing sunglasses regularly can help protect your eyes during outdoor activities such as:
- Walking
- Running
- Cycling
- Gardening
- Playing sports
- Driving
- Spending time at the beach
In certain environments, such as near water or in snowy conditions, UV exposure can be even higher due to reflection. Snow, for example, can reflect up to 80% of UV light, increasing the amount that reaches your eyes.
If you experience discomfort in bright environments, you may also notice symptoms of light sensitivity (photophobia), where sunglasses and tinted lenses can help improve comfort.
Finding sunglasses that feel right for you
The best sunglasses are the ones that feel comfortable, suit your lifestyle, and provide the protection your eyes need.
At Leightons, we offer a carefully selected range of sunglasses, including both prescription and non-prescription options. Our team will guide you through lens choices, helping you find a pair that supports your vision while reflecting your personal style.
If you are unsure where to start, it can help to explore how to choose your sunglasses lenses.
Book your appointment
If you are unsure which sunglasses are right for you, or would like to ensure your eyes are fully protected from UV exposure, our team is here to help.
Book your style consultation today and find sunglasses that are tailored to your comfort, your vision and your lifestyle.
If you are due an eye test, book your test and we will ensure your sunglasses are perfectly matched to your new prescription, supporting your vision and your eye health.





