Compared to UVB rays, how do UVA rays compare in strength?

UVA rays are indeed stronger than UVB rays in terms of their ability to penetrate the skin and their long-term effects. UVA rays penetrate deeper into the skin compared to UVB rays, reaching the dermis, which is the thicker layer of skin beneath the surface. This deep penetration means that UVA rays can lead to long-term skin damage, such as premature aging and contribute to skin cancers.

In contrast, UVB rays primarily affect the outer layer of skin (epidermis) and are the main cause of sunburn. While both types of UV radiation can have harmful effects, UVA rays are more consistently present throughout the day and can penetrate clouds and glass, leading to exposure even when it may not be sunny. Understanding the strength and effects of these rays is crucial for effective sun protection and skincare strategies.