Infrared Radiation and Your Skin: Should You Care?
The heat part of sunlight has its own effects.
The UV Index scale runs from 1-2 (low) to 11+ (extreme); protection is advised above 3.
Roughly 95% of the UV reaching Earth's surface is longer-wavelength UVA.
Frequently asked questions
What is the difference between UVA and UVB rays?
UVB rays have shorter wavelengths and cause sunburn, affecting mainly the skin's surface; UVA rays penetrate deeper and drive premature aging, wrinkles and pigmentation. About 95% of the UV reaching the ground is UVA. Both damage DNA and contribute to skin cancer, which is why 'broad-spectrum' protection against both matters.
Does UV come through windows and clouds?
Largely, yes. Standard glass blocks most UVB but lets UVA through, so windows at home, in the office, or a car's side windows still expose skin to aging rays (laminated windshields block most UVA). Clouds stop only a fraction of UV, so protect skin near windows and on overcast days.
r/AsianBeauty: 'Why do K-beauty sunscreens talk about UVA so much more than US ones?'
Sources & citations
- Dermatology Times, 'Visible Light Protection: Needs and Strategies for Diverse Patients' (2023)
- dermatologytimes.com ↗