I was making a joke. I figure the constant sight of magical aura would get a bit tiresome. Detect magic doesn't have the overwhelming aura like detect eveil does, so that's not an issue. I wonder if you would still see the aura if you closed your eyes...
Ohh. I don't know if any of those things would make the glowing blue eyes that Arcane Sight causes go away.
The spell Magic Aura, aka Nystuls magic aura. If you are used to sonstantly seeing the magical auras your character might forget that magical aura can be hidden with a minor spell...