What is the wavelength in nanometers used for treating acne in photofacial filters?

The wavelength of 420 nm is used for treating acne in photofacial filters primarily because this range falls within the blue light spectrum. Blue light is especially effective in targeting the bacteria (Propionibacterium acnes) that contribute to acne formation. The specific wavelength of 420 nm penetrates the skin effectively while also minimizing the risk of skin damage compared to other wavelengths.

Additionally, the effectiveness of blue light therapy at this wavelength is well-supported by various clinical studies, making it a commonly preferred choice among practitioners for the treatment of acne. Other wavelengths, such as those used in the choices of 515 nm, 560 nm, or 590 nm, may not provide the same level of efficacy in targeting acne-causing bacteria, as they are better suited for treating different skin conditions or concerns.