Khungu labwinobwino limatha kuyamwa poteteza ziwalo ndi minyewa m'thupi kuchokera kuwonongeka kowala. Kutha kwa kuwala kuti ulowe minofu yaumunthu kumagwirizana kwambiri ndi mawonekedwe ake ndi mawonekedwe a minofu yakhungu. Generally, the shorter the wavelength, the shallower the penetration into the skin. The skin tissue absorbs light with obvious selectivity. Mwachitsanzo, a Keratinocytes omwe ali ndi mitengo yamiyala itha kuyamwa kwambiri. The skin tissue absorbs different wavelengths of light differently, and most of the ultraviolet rays are absorbed by the epidermis. As the wavelength increases, the degree of penetration of light also changes. Infrared rays near the red light machine penetrate into the deepest layers of the skin, but are absorbed by the skin. The long-wave infrared (wavelength is 15~400μm) penetrates very poorly, and most of it is absorbed by the epidermis.
Khungucan be used to detect deep skin pigmentation problems. AKhunguAmagwiritsa ntchito spectra yosiyanasiyana (RGB, yopepuka, opepuka-yofanana ndi kuwala kowoneka bwino, ma hightemer, ma pigmentations, ma pigherher, zotupa zimatha kupezeka pakhungu.