Have you read about how those glasses work? It's kind of cool. It turns out that many color-blind people have the normal distribution of cones, but the spectr

Have you read about how those glasses work? It's kind of cool. It turns out that many color-blind people have the normal distribution of cones, but the spectral response is similar enough that the brain can't differentiate. By putting an optical notch filter in the overlap region, the difference is accentuated and the brain starts picking it up normally.