@ Jai: no, it's not the fluorescent dye that decompose, is one of the others elements .... ambient light is insufficent for decompose the H2O2 inside the sealed vial in the glowstick enough for make it non working, also in days, where instead these glowsticks (or, at least, the ones i had), if left for some days at ambient light, was not working when i broke the vial.
Anyway, it's easy to see, if you have an used one to throw away, cut it, place the liquid in a bottle, and add some H2O2, if the liquid glow again as new and stay for some time, then it's the H2O2, if instead it glow very weak or nothing at all, it's the rest.
Also, remember that the process in these videos is one of the ways for make chemioluminescence, but not the only one (take as example the "lucipherine/lucipherase" mix that fireflies uses), and we don't know exactly what and how much they place in the glowsticks .....