Blind spots in UV protection indoors and on cloudy days

Many people tend to look for sunscreen only on sunny days, but ultraviolet rays, the main culprit behind skin aging, are much more persistent than you might think. Even on cloudy days, **about 70–80%** of ultraviolet rays reach the surface, and in some cases, the UV index actually increases as the rays are reflected by the clouds.

In particular, ultraviolet A (UVA), which accelerates aging, has a long wavelength and easily penetrates glass windows. This means that even if you are indoors, if you spend time near a window, your skin is constantly being exposed to UV rays. The thought that "it's just for a moment, so it'll be fine" leads to freckles, blemishes, and loss of elasticity. Try to make it a habit to apply sunscreen as the final step of your morning skincare routine, regardless of whether you are indoors or outdoors. It is the easiest and most reliable insurance to protect your skin health.