Types of ultraviolet rays

Ultraviolet A (UVA) causes age spots, melasma, freckles, etc. in the epidermal layer of the skin, or

It causes pigmentation reactions and destroys collagen in the dermis, leading to skin aging such as wrinkles.

UV-A has a long wavelength, so it is not blocked even on cloudy days.

It continuously affects the skin regardless of the season or weather.

On the other hand, ultraviolet B (UVB) has a short wavelength, so it is said that it can be blocked when the weather is cloudy.

They say that even though the wavelength is short, the energy is much higher, so it causes burns, blisters, and skin cancer.

It would be a good idea to do your research and find the right sunscreen.