Visible Light Is the Sun-Damage Factor Nobody Talks About
Both your screen and the sun emit visible light, and it can darken skin.
Visible light is ~45% of sunlight; UV is ~5-7%; infrared makes up the rest.
The Skin Cancer Foundation notes UVA passes through clouds and ordinary window glass.
Frequently asked questions
Is visible light bad for skin?
Visible light makes up about 45% of sunlight. Research shows high-energy visible (blue) light can worsen pigmentation and melasma, especially in medium-to-deep skin tones. Tinted sunscreens containing iron oxides help shield against it, which clear sunscreens generally do not.
How does sunscreen actually work?
Sunscreens use UV filters in two groups. Organic ('chemical') filters such as avobenzone absorb UV and release it as a small amount of heat. Mineral ('physical') filters — zinc oxide and titanium dioxide — mainly absorb UV and also scatter some. Both cut how much UV reaches living skin cells.
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.
r/30PlusSkinCare: 'Is the UV index app on my phone actually accurate?'
Sources & citations
- D'Orazio J et al., 'UV Radiation and the Skin,' Int J Mol Sci, 2013;14(6):12222-12248
- wearshade.com ↗