I finally find 7 watt bulbs for my 1 gallon tank, instead of the 4 watt I've been using, and of COURSE Glitter hates the brighter light and cowers under his hide like a baby. Oh, well. Back to the 4 watts. Silly fish.
I'm sorry, but I don't think that has anything to do with him not liking bright light.
He'll come out to defend his tank from that other betta hiding in shadows he just saw. Betta are very very visual fish, he's probably hiding by preference not by need. Stay with the 4 watt and get a small desk lamp for extra light is my opinion in this case. Lights make great emergency heaters too!