I love this illustration and explanation from @cosmedocs
regarding UVA, UVB, and IR-A exposure and how it effects your skin. It’s a great reminder to always wear your sunscreen, and not all sunscreens are created equal. Choose wisely!
We know that sunlight damages the skin because of UVB, the rays that cause sunburn and can lead to skin cancer, and UVA rays, penetrate deep below the skin, causing premature ageing and are linked to melanoma.
A suncream’s SPF rating relates mainly to UVB, while its star rating – five being the highest – relates to UVA protection. However, UV light makes up only about 7% of the sun’s rays. About 50% of it is made of infrared-A (IR-A) light. IR-A appears to induce free radical formation and penetrate the skin, causing damage that can potentially lead to skin ageing. Traditional suncreams do not generally have IR-A protection
While there is no clear evidence that IR-A has a role in the development of skin cancer, if someone is concerned about skin ageing, antioxidants may limit the negative aging effects of free radicals generated by IRA. By all means look for a sunscreen with IR-A protection, but UVB and UVA protection are still by far most important.