In the middle of doing the Mages College quests in Skyrim I noticed that my magicka bar was not appearing at all despite casting spells. I found that I could cast the Flames spell indefinitely without my magicka ever draining. I looked at my Current Effects and saw that I had three extra Magicka Regen bonuses, but there was no indication of where they had come from. So I was pretty much indestructible for the next hour of playtime or so before the effects wore off.
Where would these effects have come from? Would it have been anything to do with the Eye of Magnus (which I "Activated"), just a glitch, or something else?