Ultraviolet rays have the most obvious effect on the skin and eyes of the human body. The absorption of ultraviolet rays by the skin is related to its wavelength. The shorter the wavelength, the smaller the depth of penetration into the skin, the weaker the melanin deposition after irradiation, the longer the wavelength, the greater the depth of penetration into the skin, and the stronger melanin deposition after irradiation. Due to the photochemical reaction, the photon flow with higher energy level can cause the denaturation of nucleoproteins and some enzymes in cells. Therefore, after UV irradiation, it takes 8 hours for the cells to change and show symptoms, including dry skin pain, epidermis shrinkage, and even blistering and exfoliation. Because the penetration of ultraviolet rays to the tissue is very weak, the deep tissue under the skin is less injured. But serious ultraviolet rays can cause systemic reactions such as fatigue, low fever, drowsiness and so on. Some people's skin due to UV allergy, sunlight after the occurrence of solar dermatitis (also known as sunburn), exposed area skin itching, tingling, skin desquamation, and may break scab.