In the skin, sunlight primarily damages which layers?

• A. Subcutaneous fat
• B. Epidermis and dermis
• C. Hair follicles only
• D. Sweat glands only

Answer: (B)

Sunlight affects skin depth through UV light, which penetrates to different extents depending on wavelength. UVB mainly damages the epidermis, causing sunburn and DNA mutations in epidermal cells. UVA goes deeper, reaching the dermis, where it generates reactive oxygen species and degrades collagen, contributing to photoaging. Because these two layers are where most UV-induced changes occur, sunlight can damage both the epidermis and the dermis. Subcutaneous fat lies deeper and is less directly affected, while hair follicles and sweat glands are specific structures within the dermis and are not the primary targets of UV damage.