Which statement about the short/long wavelengths is accurate?

• A. 755 nm is a short wavelength associated with high frequency and light skin; 1064 nm is a long wavelength associated with low frequency and dark skin
• B. 755 nm is a long wavelength associated with dark skin; 1064 nm is a short wavelength associated with light skin
• C. Both wavelengths are short and associated with light skin
• D. Neither wavelength affects skin color

Answer: (A)

Understanding how wavelength interacts with skin pigment is the key idea here. In laser hair removal, shorter wavelengths are absorbed more by melanin in the epidermis, while longer wavelengths penetrate deeper and are less absorbed by surface pigment. The 755 nm wavelength is shorter, so it has higher absorption by melanin and is most effective on lighter skin with lower epidermal pigment, but it carries more risk for pigment changes on darker skin. The 1064 nm wavelength is longer, penetrates deeper, and is absorbed less by epidermal melanin, making it safer for darker skin types while still targeting hair.

So the statement that correctly reflects this is: 755 nm is a short wavelength with higher frequency that suits light skin, and 1064 nm is a long wavelength with lower frequency that suits dark skin. The other options misstate the wavelength order or the way skin color relates to wavelength, and the idea that these wavelengths don’t affect pigment is incorrect.