How does melanin absorption change with increasing wavelength?

How does melanin absorption change with increasing wavelength?

• A. Increases
• B. Decreases
• C. Remains constant
• D. Oscillates

Answer: (B)

Melanin absorbs more strongly at shorter wavelengths and well less as wavelength increases into the red and infrared. This happens because melanin’s absorption is higher for higher-energy photons and tapers off with lower-energy photons found at longer wavelengths. So, when you move to longer wavelengths, melanin takes up less of the light. That’s why the correct idea is that melanin absorption decreases as wavelength increases. In practice, this means longer wavelengths interact less with epidermal melanin (reducing pigment risk) while other factors, like water absorption, become more relevant at very long wavelengths.

Melanin absorbs more strongly at shorter wavelengths and well less as wavelength increases into the red and infrared. This happens because melanin’s absorption is higher for higher-energy photons and tapers off with lower-energy photons found at longer wavelengths. So, when you move to longer wavelengths, melanin takes up less of the light. That’s why the correct idea is that melanin absorption decreases as wavelength increases. In practice, this means longer wavelengths interact less with epidermal melanin (reducing pigment risk) while other factors, like water absorption, become more relevant at very long wavelengths.