Fig 3. Transmittance of different spectacle lenses as measured by a spectrophotometer.

Selective blue-filtering (S-BF) lens reduced 17% more visible blue light compared to the ultraviolet-filtering (UVF) lens, and reduced 35% more blue light compared to the CR39 lens. The blue filter significantly reduced the blue spectrum. The CR39 lens did not have any coating and allowed most blue and some UV light to pass through. A control without any lens allowed 100% transmittance for all wavelengths.