Those do not work for everyone. I bought some glasses from this company for my father, both he and a colorblind colleague could not see any improvement apart from a slight contrast increase after a few hours of wearing them. One of them was slightly red-green colorblind, the other one had a much stronger red-green color blindness. The company seem to exaggerate a lot the effect of their lenses with carefully selected overenthusiastic testimonies. The good thing is that the glasses could be returned and refunded.