Light makes no difference in the reproductive cycle of ich. The ich parasite infests a fish via it's gills, and then slowly makes it's way through the muscle. It forms a cyst on the skin of the fish, which drops off and lands in the substrate. This cyst hatches into many free swimming tomites. The tomites make their way through the water in search of a fish to re-infect. The time this process takes is temperature dependant--higher temps makes it go faster. The tomites are the only stage we can effect with medications.
However, if you saw worms, it wasn't ich. With the exception of the cysts (the white crytals on the skin of the fish), the life stages of the ich parasite are too small to be seen by the naked eye.
Sorry--I can't identify what you do have, but it isn't ich.