OK, maybe I didn't read throughly enough.Sorry for the confusion. The melatonin is to help with sleep. But initially there was some question about whether high doses made one's light sensitivity worse.
Will read the entire thread as I have experimented with Melatonin to fix my delayed sleep phase syndrome.
For that, taking a smaller dose at sunset or 6 hours before bed works better for me than lager doses closer to sleep time.
Melatonin also converts to serotonin and visa versa if that wasn't mentioned already.