I would want something like this:
No night-eye: http://www.tesnexus.com/downloads/images/36407-4-1294000860.jpg
Night-eye shader: http://www.tesnexus.com/downloads/images/36407-1-1294000928.jpg
That was my idea too. But now that I'm thinking about it, this at such moderate levels would be a nice constant effect for Khajits, and call it CatsEye instead?
But NightEye, being the cheapest spell would be what we already have but be blinding in light like washout effect on night vision goggles. And then toss in DeamonEye as well, for heat vision. And a MagicEye to see magical equipment glow. So in total, 5 vision spells in total at varying cost:
Novice - Light - A torch that increases with skill. Strong as a torch at 25, strong as a lantern at 50, and preferred above.
Apprentice - Night Eye - Blueish tint, long reach with high skill, but lights will be blinding, so it's not THAT good.
Journeyman - Magic Eye - Purple tint, flatter than Night Eye, but enhanced items will appear to glow. Know thy enemy
Expert - Animal Eye - Greenish tint, maximum reach always (not affected by skill), but you won't get blinded by light since it blends.
Master - Demon Eye - Reddish tint, maximum effect always, and heat sources will stand out against cooler background.
GrenaMaster - Detect Life - Seriously?