There are two types of UV light that can harm your skin - UVA and UVB.

太阳光线中有两种紫外线会对你的皮肤造成伤害，即uva和uvb。

youdao

They should block 99-100% of the UVA and UVB radiation.

太阳镜应该阻挡99 - 100%的紫外线或的辐射。

youdao

Check the ingredient list for zinc oxide or titanium dioxide; both physically block UVA and UVB rays.

注意成分表中是否含有氧化锌或二氧化钛，这两者都能阻挡紫外线A和B。

youdao

Both UVA and UVB rays contribute to skin cancer, but the damage caused by UVA rays is harder to measure.

WSJ: European Sunscreen Roadblock on U.S. Beaches

New sunscreen labels in effect this year require a pass-fail test for UVA and UVB protection.

WSJ: European Sunscreen Roadblock on U.S. Beaches

Rules implemented last year by the U.S. Food and Drug Administration say that only sunscreens that are broad-spectrum protecting against both UVA and UVB rays and that have an SPF of 15 or higher can claim to reduce the risk of early skin aging and skin cancer.

WSJ: Sunscreen Each Day Stops Wrinkles