The portion of the visual light spectrum most associated with light sensitivity and migraine occurs at wavelengths around 480nm. Our SpectraShield FL-41 lens technology blocks this portion of the spectrum. SpectraShield FL-41 is different from a green lens. There was a small study out of Harvard that showed a second response portion at 590nm which the green lenses attempt to block. The biggest problem with blocking this light is the lenses are too dark in most environments. Blocking too much light unnecessarily can cause or worsen dark adaptation of the eyes. If you have a negative response to fluorescent light, there is more clinical data showing FL-41 tints are the most effective.
We want to block only the bad light and let as much good light in as possible so that the lenses do not worsen the light sensitivity. We do not recommend color specific lenses or wearing outdoor sunglass lenses inside. You may be interested in comparing filters at http://fluxometer.com.
Our SpectraShield FL-41 works and is effective for about 90% of our customers. All non-prescription Axon Optics frames have the 30 day return policy and are covered by a 1 year warranty. You can shop our glasses at http://www.axonoptics.com/product-category/migraine-glasses/
Please let me know if you have any other questions.