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What does UV400 actually mean? A plain-English breakdown

What does UV400 actually mean? A plain-English breakdown

UV Protection · Plain English

What does UV400 actually mean? A plain-English breakdown

UV400 is on every decent pair of sunglasses — but most people who buy it cannot explain what it means. This is the complete, jargon-free explanation.

🕑 5 min read☀ UV protection📖 Explainer

In this article

  1. What UV400 means exactly
  2. UVA vs UVB — what is the difference
  3. UV400 vs 100% UV protection — same thing?
  4. Dark lenses and UV — the myth
  5. Does UV400 protect against blue light?
  6. How to verify your sunglasses have UV400

What UV400 means exactly

UV stands for ultraviolet — a form of electromagnetic radiation with wavelengths shorter than visible light. The human eye cannot see UV, but the cells of the eye and eyelid absorb it. Long-term absorption causes damage.

The 400 in UV400 refers to 400 nanometres — the wavelength at which ultraviolet light ends and visible light begins. UV400 labeling means the lens blocks all UV radiation from 0 to 400nm: 100% of both UVA and UVB rays.

In one sentence
UV400 = blocks all ultraviolet light up to 400 nanometres = 99–100% UVA and UVB protection. That is the highest level available in consumer sunglasses.

UVA vs UVB — what is the difference

Type Wavelength Effect on eyes Penetration
UVA 315–400nm Cataracts, macular degeneration — long-term cumulative damage Penetrates deep into the eye, passes through clouds and glass
UVB 280–315nm Photokeratitis (corneal sunburn), acute damage Mostly absorbed by the atmosphere but significant at high altitudes and near water

UV400 blocks both. Sunglasses that only specify UV protection without the 400 standard may only partially block one or both types.

UV400 vs 100% UV protection — same thing?

UV400
Blocks all UV up to 400nm. Explicit, verifiable standard. Covers 99–100% of UVA and UVB.
100% UV protection
Same thing in practice. Both refer to full UVA+UVB blocking. UV400 is the more specific label.

Use either label to confirm protection. What you want to avoid is any sunglasses with no UV labeling at all, or vague labels like UV resistant without a percentage or standard.

Dark lenses and UV — the myth

Important
Lens darkness has absolutely no relationship to UV protection. A dark lens without UV400 coating provides no UV protection. Worse — your pupil dilates behind the dark lens, allowing more UV radiation to enter the eye than without glasses at all.

The UV blocking comes from an invisible coating applied to the lens — not from the tint. A completely clear lens with UV400 coating protects your eyes identically to a dark lens with the same coating.

Does UV400 protect against blue light?

No. UV400 and blue light protection are two separate things. UV radiation sits at 0–400nm — invisible to the human eye. Blue light sits at 400–500nm — the lower end of the visible spectrum. They require different coatings.

Rawbare offers dedicated blue-cut frames — the Timeless Bluecut RB2446 and Rogue Shades Bluecut RB2533 — which add blue light filtering on top of standard UV400 protection.

How to verify your sunglasses have UV400

Check the product tag, sticker, or description for explicit UV400 or 100% UV protection labeling. If the product says only UV protection with no standard or percentage, it may offer partial or no protection. All Rawbare sunglasses include UV400 as a standard across every frame from Rs.799 upward — verified, not aspirational.

Rawbare guarantee
Every pair in the Rawbare range — from Rawbare Junior at Rs.799 to Rawbare Luxe — includes UV400 protection as standard. Shop the full collection.

Key takeaways

✓ UV400 = blocks all UV up to 400nm = full UVA+UVB protection
✓ UV400 and 100% UV protection mean the same thing
✓ Lens darkness has zero connection to UV protection
✓ Dark lens without UV coating is worse than no glasses
✓ UV400 and blue light protection are different — separate coatings

Frequently asked questions

Q1 What does UV400 mean on sunglasses?
UV400 means the lenses block all ultraviolet light up to 400 nanometres in wavelength — covering 99 to 100 percent of both UVA and UVB rays. It is the highest level of UV protection available and the standard you should always look for.
Q2 Is UV400 the same as 100% UV protection?
Yes — UV400 and 100% UV protection mean the same thing in practice. Both indicate that the lenses block virtually all ultraviolet radiation. UV400 is the more specific and verifiable label since it references the exact wavelength range being blocked.
Q3 Does UV400 mean the lenses are dark?
No. Lens darkness and UV protection are completely unrelated. A clear or lightly tinted lens with UV400 coating protects your eyes just as well as a very dark lens with UV400. A dark lens without any UV coating is actually more dangerous.
Q4 How do I know if my sunglasses have UV400 protection?
Check the tag, sticker, or product description for UV400 or 100% UV protection labeling. If there is no UV labeling at all, assume no meaningful protection. For Rawbare sunglasses, UV400 is standard across every frame in the range.
Q5 Does UV400 protect against blue light?
No — UV400 blocks ultraviolet radiation which is invisible to the human eye. Blue light is visible light in the 400 to 500 nanometre range. They are different parts of the spectrum requiring different lens coatings. Rawbare's blue-cut frames address blue light separately.

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