Lenses, not just frames
Blue-Light Filters in Sunglasses: Marketing vs Light
Sunglasses already cut a lot of blue because they are dark. An extra ‘HEV’ stamp is usually a colour story on top of UV400, not a second sun.
Updated 27 Aug 2026 · 6 min read · blue light filter in sunglasses
Dark glass is already a blue diet
If the lens is category 3, a large fraction of 400–500nm visible light is already gone. Adding a ‘blue filter’ line to the hangtag is often describing the tint you bought. Brown and G-15 cut blue more obviously than a neutral grey; that is colour, which drivers should notice around brake lights.
Indoor clear blue-light coats are a different, weaker product. Do not wear them outside as sun. Do not assume a sun HEV coat is doing extra UV — check UV400 separately.
What is worth paying for on a sun lens
UV400. A tint dark enough for the job. Polarization if glare is the job. A wrap if coverage is the job. Mirror if you want it. HEV marketing is last, if it is even on the list.
| Claim on sunwear | Pay attention? |
|---|---|
| UV400 / 100% UV | Yes |
| Polarized | If you want glare cut |
| Category 3 | Yes for bright sun |
| HEV / blue-light filter | Optional colour |
| ‘Medical blue block’ | Marketing on a dark lens |
Sleep, screens, and the crossover pitch
You will not sleep better because your beach pair had an HEV logo. Night screens are a software-and-amber problem — sleep glasses. Day sun is UV and glare. Keep the hangtags in their lanes.
Questions, answered
- Do I need HEV plus UV400?
- You need UV400. HEV on a dark lens is usually redundant. If the tint colour suits you, fine.
- Grey or brown for blue cut?
- Brown cuts more blue and warms the scene. Grey is more colour-true. Neither replaces the UV stamp.
- Can indoor blue-light glasses be worn in sun?
- No. They are not a sun filter. Wear UV400 sunwear outside.
