I want to ask a question about the coloration of eyeglasses lenses, I heard that, usually, it only take several minutes to dye the lenses, I wonder how long will the lens get to fade because of such a short time of dyeing?

Really and truly, the lenses can't get faden easily, the mixture which are blended with dye and lenses are heated up at 100 degree centigrade, so it can't go faden easily, but when comes to acetone, things will change!