Introduction: Ultraviolet (UV) radiation from the sun has both beneficial and harmful effects on the human body. While it is essential for the synthesis of vitamin D, excessive exposure can lead to skin damage and an increased risk of skin cancer. The extent of UV penetration into the skin layers is crucial in determining the level of damage caused. This article explores the depth of penetration of UV radiation into the skin and the factors that affect it. Depth of Penetration: The skin consists of three layers: the epidermis, dermis, and subcutaneous tissue. UV radiation penetrates the skin's outermost layer, the epidermis, and can extend into the dermis layer. The depth of penetration depends on the wavelength of the UV radiation. UVB radiation, with a wavelength of 280-320nm, primarily affects the epidermis and does not penetrate deep into the skin. In contrast, UVA radiation, with a wavelength of 320-400nm, penetrates deeper into the skin and can reach the dermis layer. Facto...