What is the effect of the UV light in the airway?

The UV light works in a lower frequency (wavelength) than white light, outside of the visible spectrum. It overpowers the higher end of the white light spectrum where higher frequency yellow and red colors can cause glare, and produce a whitewash effect in the visual image. The UV light reduces scatter from higher frequency light, and helps provide a clear, clean, and crisp view of the airway.