Thats was my thought too. But then this kind of filter is really expensive. en-chroma glasses use a 100 layer interference filter to achieve that kind of band pass. A pair of their glasses retail in new zealand at $800 NZD A screen sized interference filter like that would most likely be unaffordable. Also a monitor would have to be super bright too be useable with the full strength version of their glasses. I am guessing it would be much cheaper to just use a back light on the monitor that emits the spectra needed in the first place using led's. And not go to the expense trying to remove those spectral bands using expensive filters. Peter On 9/11/2015, at 1:33 pm, Sean McGrath <sean@manybits.net<mailto:sean@manybits.net>> wrote: The image at http://d1h1nw9upgtapw.cloudfront.net/wp-content/uploads/2015/03/enchromacx.p... shows an optical band pass filter with steep cutoffs. I may be possible to apply that to an overlay for a display, "glasses" for the light source. Sean McGarth sean@manybits.net<mailto:sean@manybits.net>