UVA and UVB rays: what they are and why you need protection from both
Natali Profumeria · 1 min read · November 1, 2026
The sun reaches us with different types of rays. Two matter most for the skin: UVB and UVA. They behave differently, and a good sunscreen should protect against both.
UVB: the ones that burn
UVB rays hit the surface layers of the skin. They are responsible for redness and sunburn, and are more intense in summer, during the middle of the day, and at high altitudes. The SPF rating measures protection against these rays.
UVA: the ones you don't feel
UVA rays penetrate deeper. They don't burn, which is why we underestimate them, but they are the main cause of photoaging: wrinkles, loss of elasticity, and dark spots. They are present all year round, even in winter, and pass through clouds and the glass of windows and car windows.
How to recognize good UVA protection
In Europe, a sunscreen that also provides good protection against UVA rays displays the "UVA" symbol inside a circle: this means that the UVA protection is at least one-third of the SPF value. On some products, you may also find the PA rating with plus signs (PA+++, PA++++): this is another scale, used mainly in Asia, for the same type of protection.
What this means in everyday life
In summer, at the beach or in the mountains, you need a broad-spectrum sunscreen with a high SPF. For the rest of the year, on the face, a day cream with UVA protection helps prevent dark spots and signs of aging, especially if you spend a lot of time outdoors or near a window.
Frequently asked questions
What is the difference between UVA and UVB rays?
UVB rays hit the surface of the skin and cause sunburn; UVA rays penetrate deeper and mainly cause aging and dark spots, even without burning.
Do UVA rays pass through clouds and glass?
Yes: UVA rays are present all year round, even when the sky is overcast, and pass through the glass of windows and car windows.
How can I tell if a sunscreen protects against UVA rays?
Look for the "UVA" symbol inside a circle on the packaging: it indicates that the UVA protection is adequate relative to the SPF.