Ultraviolet (UV) therapy, also known as phototherapy, has become a well-established and effective treatment for various skin conditions. While UV light is often associated with sunburn and skin damage, controlled exposure to specific wavelengths of ultraviolet light can actually bring significant therapeutic benefits. UV therapy is primarily used to treat chronic skin diseases such as psoriasis, vitiligo, eczema (atopic dermatitis), and even some forms of acne. The treatment involves exposing affected areas of the skin to UVB or UVA light under medical supervision. The most commonly used type is narrowband UVB therapy, which emits a specific wavelength (around 311–313 nm) that is highly effective for treating many skin disorders. One of the key benefits of ultraviolet therapy is its ability to slow the overproduction of skin cells. For example, in psoriasis, the body creates skin cells too quickly, leading to thick, scaly patches. UVB light helps regulate this process, reducing inflammation and scaling. Similarly, in vitiligo, UV therapy can stimulate pigment cells (melanocytes) to help restore skin color in depigmented areas. UV therapy is generally considered safe when administered in a clinical setting. Treatments are usually brief and occur several times a week for a few weeks or months, depending on the condition and its severity. Protective eyewear is worn during sessions to shield the eyes from potential damage. In some cases, treatments are combined with topical or oral medications to enhance results—especially in PUVA therapy, where UVA light is used in combination with a photosensitizing drug called psoralen.