This is something that really, really annoys me.

The fact that the main character-- Actually no. 99% of the characters don't have brown eyes.

Seriously, not even joking. They always seem to have blue/green/grey/ heterochromia type of eyes.

Even though most of the population has brown eyes!

I've only seen one story. One story where the main character had dark brown eyes. That was a miracle!

It usually goes like this:

Mary Sue: I ran my hands through my blonde hair and look at my reflection. My ocean blue/ grass green/ ice grey/ heterochromia eyes stare at me.

Gary Stu: My emerald green/ water blue/ crystal grey/ heterochromia eyes stare at hers.

Evil protagonist (usually the popular girl): My sky blue eyes are the prettiest! (For some reason, they always seem to have blue eyes)

I think you get what I mean. Just make most of the characters have brown eyes for God's sake! -_-

Note: Heterochromia eyes are the type of eyes with one eye being green/blue/brown but the other has a completely different colour. (It's usually one green one blue, or one blue and one brown)