UV400 Protection: Everything You Need to Know to Protect Your Eyes
Sunrise Ibiza
We choose sunglasses for their style, but their first mission is invisible: protecting your eyes from radiation you can’t see or feel. Understanding UV protection means making sure a beautiful pair is also a safe one. Here is the essential guide, without unnecessary jargon.
This guide is the cornerstone of all our advice: whether you choose according to your face shape, lens colour or frame type, UV protection remains the non-negotiable criterion. Let’s see why.
What exactly are UV rays?
The sun emits ultraviolet (UV) radiation, invisible to the eye, which is classified into three families: UVC rays (fortunately filtered by the atmosphere), UVB rays and UVA rays, which reach our skin and eyes. UVB rays are the most energetic at short range; UVA rays penetrate more deeply. Both can damage the eyes, and their intensity increases at altitude, near water, sand or snow, which reflect light.
Why protect your eyes from UV rays
Repeated exposure to UV rays without protection can cause discomfort and eye fatigue in the short term; in the long term, it is associated with several forms of damage to the eyes and eyelids. The skin around the eyes, which is very delicate, is sensitive too. The right reflex is therefore not seasonal: whenever the sun is bright, protective lenses are useful — including in winter and on hazy days, because UV rays pass through clouds.
UV400: the label that really matters
This is the heart of the matter. UV400 means that the lens blocks all ultraviolet rays up to a wavelength of 400 nanometres — in other words, all UVA and UVB rays. A pair labelled UV400 (or “100% UVA/UVB”) offers maximum protection. It is the first thing to check, even before colour or shape.
Crucial point: lens tint has nothing to do with UV protection. A clear lens can be UV400; a very dark lens may offer no protection at all. Worse still, dark lenses without a UV filter are dangerous: the darkness dilates the pupil and lets in more harmful rays. So never judge a pair by the intensity of its tint alone.
Lens categories (0 to 4)
Not to be confused with UV protection: the category indicates the amount of visible light the lens lets through, in other words its “darkness level”.
- Category 0: very clear lenses (0–20% of light filtered), for comfort or aesthetics.
- Category 1: low light, overcast weather.
- Category 2: medium brightness, mid-season.
- Category 3: strong brightness — the benchmark for summer, the beach and the Mediterranean.
- Category 4: extreme brightness (high mountains, desert) — not permitted for driving.
A pair can be both UV400 (total protection) and category 3 (darkness suited to summer): this is the ideal combination for most uses.
Polarisation and UV: don’t confuse them
Polarised lenses are often presented as an added plus, and they are — but for a reason other than UV. Polarisation reduces glare caused by light reflecting off horizontal surfaces (water, road, car bonnet). It therefore significantly improves comfort by the sea or behind the wheel. Important: a polarised lens is not necessarily UV400, and vice versa. These are two separate properties; ideally, you want both.
Standards and markings to know
In Europe, compliant sunglasses carry the CE marking, which confirms that safety requirements have been met, including UV protection and category. Look for this information on the label, the temple or the leaflet. A reliable pair clearly states its UV protection (UV400 / 100% UVA-UVB), its category and its compliance.
How to check a pair’s protection
- Read the label: look for “UV400” or “100% UVA/UVB” and the category.
- Check the CE marking and the presence of an information leaflet.
- Be wary of unusually low prices with no information at all: a dark tint guarantees nothing.
- If in doubt, an optician can measure a pair’s real protection in just a few seconds.
At Sunrise Ibiza, protection is designed as a prerequisite, not an option: discover our styles in the complete collection.
Common misconceptions
- “The darker they are, the more protective they are.” False: tint has nothing to do with UV rays.
- “On cloudy days, you don’t need sunglasses.” False: UV rays pass through clouds.
- “Children don’t need protection.” Quite the opposite: their eyes are more sensitive and let in more UV rays. Suitable protection is essential.
- “Polarised = protected from UV.” Not necessarily: also check for the UV400 label.
Frequently asked questions
What does UV400 mean on sunglasses?
It means the lenses block all UV rays up to 400 nanometres, or 100% of UVA and UVB rays. This is the maximum level of protection and the criterion to check first.
Does a dark tint protect better against UV rays?
No. The colour and intensity of a lens have no link to UV protection. Only the UV filter matters. A dark lens without UV400 is even riskier than wearing no sunglasses at all.
What is the difference between lens category and UV protection?
The category (0 to 4) indicates the darkness level, meaning the visible light filtered. UV protection (UV400) concerns invisible rays. A good summer pair combines UV400 and category 3.
Are polarised lenses useful?
Yes, for reducing glare on water or the road. But polarisation does not replace UV protection: check that the pair is also UV400.
Should you wear sunglasses in winter?
Yes, when the light is strong. UV rays are present all year round and snow, like water, strongly reflects light, increasing exposure.
In summary
Remember the essentials: check for the UV400 label, choose the category according to brightness (3 for summer), add polarisation for comfort if you can, and never judge a pair by the colour of its lenses. Once you have these basics, you can choose your style with complete confidence — by face shape or by lens colour. Discover protective, stylish pairs in the Sunrise Ibiza collection.
