Paul H.
Gunnar will not provide light transmittance data for their lens
Gunnar's marketing material states how much light is blocked at the 450nm wavelength. While this is very useful information, it is only telling you the lens performance for a single wavelength. I recommend sticking with manufacturers that publish the performance of their lens over the entire visible spectrum, not just a single wavelength. Note that the blue light spectrum runs from 380nm to 500nm wavelengths. Current studies are showing that any blue light from 400 to 450nm can cause retina damage. Blue light from the entire blue spectrum (380nm to 500nm) is shown to effect sleep quality (blue light is good in the morning, bad at night), cognitive functions (tied to sleep quality) and mood (blue light helps prevent Seasonal Affective Disorder). Thus it is critical to understand how your lens performs over the entire blue light spectrum, not just at a single wavelength I reached out to Gunnar asking for their light transmittance data (a graph that shows how much light the lens blocks/passes over the entire visible spectrum) for their Amber Max BLPF 98 lens. They did respond promptly, but sent information for their Amber BLPF 65 lens. I wrote back thanking them for the info, but pointed out that I was asking about the Amber Max BLPF 98 lens. They wrote back saying they did not have that data for the Amber Max BLPF 98 lens. Given that blue light protection is important for critical health reasons I suggest sticking with manufacturers that test their lens over the full visible light spectrum and publicly publish the results. Several of Gunnar’s competitors openly publish the light transmittance graph for their lens on their websites
Response from GUNNAR OptiksNov 18, 2019
Hello Paul, We take our Blue Light Protection Factor™ (BLPF) measurements at the peak of the blue light spectrum (450nm) where exposure has the most significant impact on melatonin production, affecting the body’s natural sleep cycle. While we are concerned with protecting eyes against the entire blue light range, we like to present an easy to understand measurement to compare each lens tint against the others. Our GUNNAR Amber Max Lens offers a Blue Light Protection Factor™ (BLPF) of 98, blocking 99.9% of blue light at 380 nm, 98% of Blue Light at 450 nm, and 91% of blue light at 500 nm. Warm regards, Team GUNNAR




