Depending on if there are caps, or where they are/how arranged, here we go on text exotes:
1.)
o.o : blank stare, as in "You've just lost me" Or "I care about this...Why, again?"
2.)
O.o ; o.O : Confusion, usually used together.
3.)
O.O : Suprise, shock.

shock, puzzlement, misunderstanding; raised eyebrow, skepticism

generally used in online chatting

An anime style smiley used to express shock, or

A surprised, disturbed or confused emoticon.

it depends. either you use: o.o, O.O, O.o, or o.O there's a good chance it's for something you couldn't believe you just heard.

–emoticon

1. A commonly emoticon used on the internet to indicate confusion
2. A surprised look
3. (used to specify the feeling where you don't know what's going on)
4. Over-used in instant conversations like the internet short form of laugh out loud; "lol".

This emoticon has been used in several different ways. Some of them, you may recognize:

o.o , o.O , O.o , o_o , o_O , O_o , 0.o , o.0 , o_0 , 0_o , 0.0 , O_O , 0_0 , O.O

Aside from the ones given above, there have been several people who customized them. For example; o_______o , o_o;; , o_o" and so forth...

You probably typed this because you were bored and therefore clicked on the first link on your search engine which is how you are reading this and you probably know what it means, If not, then continue reading below :)

It means to be suprised, like this ---> O.O <--- (eyes open wide)

Or to be looking at someone in a "one eyebrow up" kind of way like this ---> O.o <--- (It may be flipped to this ---> o.O <--- although It does means same thing) it's a way of saying "whaaat?" or "I don't know what you're talking about" or even "don't look at me, I don't know!"

Or it can mean "I'm confused and don't understand the current situation" like this ---> o.o <--- (eyes wide open but sort of small and hidden) this may be due to confusion or maybe simply trying to look cute.

Hope this helped...Everyone has their own opinion of what it means :D <---Happy face haha :D