For viewing your own in-game character thats using invisibility or stealth abilities/actions in eso; it currently makes a character look like shadows and glowing effects still shows and such. In eso it's pretty easy to notice a character sneaking around.
If invisibility in eso looks more like the invisibility effects that guild wars 2 has: image below.
Character looks like she or he is made completely out of 3d transparent glass with other extra effects hidden such as glow. That in my opinion would make invisibility and stealth abilities look more realistic.