How to Pick the Best Sunglasses for Your Face Shape
When you pick the best sunglasses for your face shape, style is only half the decision. The other half is protection, and that starts with a question many buyers ask: what does UV400 mean? Buyers often confuse UV protection, polarisation and lens darkness, yet they do completely different jobs. This guide briefly covers how to pick the best sunglasses for your face shape, then explains what UV400 means, how it differs from polarised lenses and tint, and why dark lenses without UV protection can be worse than wearing none at all.
Key Takeaways
- UV400 means the lenses block ultraviolet light up to 400 nm, covering UVA and UVB.
- Polarisation cuts glare; it doesn't block UV on its own.
- Lens darkness has nothing to do with UV protection.
- Dark lenses without UV protection can let more UV reach your eyes.
- Price doesn't decide protection; the label and standards do.
Picking the Best Sunglasses for Your Face Shape
Start with fit: frames about as wide as your face at the temples, with the top near your brow line and the bottom clear of your cheeks. Then use contrast, such as angular frames for round faces and curved frames for square ones. Our full face shape guide for glasses and sunglasses covers every shape in detail. Once you've found a style that suits you, check the lenses protect your eyes.
What Does UV400 Mean?
Ultraviolet (UV) light is invisible radiation from the sun. The UV that reaches us is mainly UVA (about 315 to 400 nanometres) and UVB (about 280 to 315 nanometres). UV400 means the lenses block ultraviolet light with wavelengths up to 400 nm, which covers both UVA and UVB. In practice, UV400 and "100% UV protection" mean the same thing.
Why UV protection matters
Long-term UV exposure is linked to eye problems such as cataracts and growths on the surface of the eye, and short intense exposure, such as on snow, can cause painful sunburn of the eye. The skin around your eyes is also vulnerable. Sunglasses with UV400 lenses are a simple way to reduce these risks.
UV400, Polarised and Tinted: Three Different Things
| Property | What it does | Benefit | Notes |
|---|---|---|---|
| UV400 / 100% UV protection | Blocks ultraviolet light up to 400 nm, covering UVA and UVB | Protects eyes from UV damage | Essential for every pair |
| Polarised | Filters horizontally reflected glare | Comfort and clearer vision near water, roads and snow | Optional; doesn't block UV on its own |
| Tint (darkness) | Reduces visible light | Comfort in bright conditions | Darkness says nothing about UV protection |
Why Dark Lenses Without UV Protection Are Worse Than None
This is the most important safety point. Behind dark lenses, your pupils widen to let in more light. If the lenses don't block UV, those wider pupils allow more ultraviolet light to reach the inside of your eyes than if you weren't wearing sunglasses at all. Darkness is not protection: always check for a clear UV rating.
UV400 vs Polarized
Polarised lenses contain a filter that blocks glare reflected off flat surfaces such as water, wet roads, car bonnets and snow. That makes vision clearer and more comfortable, especially for driving, fishing and golf. But polarisation doesn't block UV by itself. Good polarised sunglasses also have UV400 protection; check the label for both.
When polarised lenses aren't ideal
- Reading some digital screens, which can look dark or patchy.
- Spotting icy patches on slopes, where glare can be a useful warning.
- Some pilots and equipment operators who need to read specific displays.
Lens Darkness Categories
Sunglasses are often rated by filter category, which describes how much visible light they let through, not UV protection.
| Category | Tint | Best for |
|---|---|---|
| 0 | Clear or very light | Indoors, overcast days |
| 1 | Light tint | Low sun |
| 2 | Medium tint | Everyday sunshine |
| 3 | Dark tint | Bright sun, beach, snow |
| 4 | Very dark | High mountains and glaciers; not suitable for driving |
Lens colours
| Colour | Effect | Best for |
|---|---|---|
| Grey | Natural colours, even dimming | Everyday use and driving |
| Brown or amber | Boosts contrast | Golf, cycling, variable light |
| Green | Balanced contrast and colour | General outdoor use |
| Yellow | Brightens low light | Overcast days; not for night driving |
Are Cheap Sunglasses Safe?
Price doesn't decide UV protection. Inexpensive sunglasses can offer full UV400 protection if they're properly made and tested. The risk comes from unlabelled or poorly made lenses, often sold without any information about protection. Buy from sellers who state full UV protection clearly, and look for recognised standard markings on the label or frame.
How to Check Sunglasses UV Protection
- Read the label: look for a clear UV rating.
- Check for standard markings: recognised standards for sunglasses, such as ISO 12312-1 in many countries or ANSI Z80.3 in the US, show the lenses have been tested.
- Ask an optician: many can measure UV transmission with a meter.
- Don't rely on home tests: UV torches and banknote tests can show some UV blocking but can't confirm full protection.
Where You Need UV Protection Most
- Snow and water: both reflect UV, increasing exposure.
- High altitude: UV is stronger the higher you go.
- Midday: UV is strongest around the middle of the day.
- Cloudy days: UV passes through cloud, so protection still matters.
What Does UV400 Mean on a Label?
If you're still asking what does UV400 mean when you see it on a tag, think of it as a promise that the lenses block ultraviolet light up to 400 nm. Some labels say "100% UVA/UVB protection" instead, which means the same. Be cautious of vague claims such as "UV coated" or "anti-UV" without a rating, and of sunglasses with no label at all.
Caring for Your Sunglasses
Scratches don't usually remove UV protection built into the lens material, but some coatings can wear. Clean lenses with a microfibre cloth and lens cleaner rather than clothing, keep sunglasses in a hard case, and avoid leaving them on a hot car dashboard, which can warp frames and damage coatings.
Common Mistakes
- Assuming darker lenses give more protection.
- Treating polarised as the same as UV protection.
- Buying unlabelled sunglasses.
- Wearing very dark lenses for driving.
- Skipping sunglasses on cloudy days.
Now you know what UV400 means, you can pick the best sunglasses for your face shape and be confident they protect your eyes.
UV400 Sunglasses From Global Swanky
Browse more in our Sports and Outdoors collection.
1. UV400 Fashion Oval Frameless Sunglasses
The UV400 Fashion Oval Frameless Sunglasses for Eye Protection are $10.19, with full UV protection in a light, frameless style.
2. UV400 Polarized Safety Sunglasses
The UV400 Polarized Safety Sunglasses with Anti-Glare Protection are $11.92, combining full UV protection with polarised lenses.
3. Square Polarized Sunglasses
The Square Polarized Sunglasses for Outdoor and Daily Wear are $17.16, for glare reduction in everyday use.
4. Outdoor Polarized Sunglasses with Cap Clip
The Outdoor Polarized Sunglasses with Cap Clip and UV Protection are $48.90, which clip to a cap for golf and outdoor sports.
Frequently Asked Questions
What is a UV protection sunglasses rating?
Look for a label such as UV400 or 100% UV protection, which means the lenses block ultraviolet light up to 400 nm, covering both UVA and UVB. Standard markings on the frame or label also show the lenses meet recognised safety standards.
Polarised vs UV protection: what's the difference?
UV protection blocks invisible ultraviolet light that can damage your eyes. Polarisation reduces glare from reflective surfaces like water and roads. They're separate features, so choose sunglasses with UV protection, and add polarisation if glare bothers you.
Are cheap sunglasses safe?
Price doesn't decide UV protection. Inexpensive sunglasses can block 100% of UV if they're properly made and labelled. The risk is unlabelled or poorly made lenses, so buy from reputable sellers and check for UV400 or 100% UV protection.
UV400 vs polarized: which is better?
They do different jobs. UV400 protects your eyes from UV damage and is essential. Polarisation improves comfort by cutting glare. The best choice for water, snow and driving is often both.
How can I check sunglasses UV protection?
Check the label for UV400 or 100% UV protection and recognised standard markings. An optician can measure UV transmission with a meter. Home tests with UV torches or banknotes aren't reliable for confirming full protection.