Painless? Yes. UVA radiation cannot be felt directly; it passes through the cloud barrier and is less noticeable in the short term than UVB (as it does not cause sunburn).It penetrates deep into the skin, reaching all the way to the dermis cells, and does some real damage.For example: photoaging (with loss of elasticity and firmness), solar allergies (such as benign summer light eruption), pigment irregularities (dark spots) and even cancer. It is therefore essential, when exposed to the sun, to go for double sun protection: anti UVA and UVB. This should be chosen according to your skin type: SPF 50 if your skin is very pale, 50 to 30 when your skin is first exposed to the sun, then 30 to 15 for intermediate skin and SFP 20 for dark skin.