Brown eyes are not considered as much attractive as other more 'exotic' eye colours like green, blue, grey or even hazel. I think brown eyes can be just as attractive but unfortunately not many are into brown eyes as much because they are common. Which is unfortunate as most of the population has brown eyes so I think it's infair.
In general, I think brown eyes are more attractive than green or blue. But I think it mainly has to do with how your eyes match the rest of your face. Dark eyes are usually more attractive in people with darker hair and darker skin tone while light eyes look better in people with lighter hair and skin tone.
That being said, it's really not a big deal. Anyone could buy colored contacts if it bothers them that much.
Brown eyes, you seem them everywhere.. Because its the most common type of color in the eyes.. So when you see green or blue eyes!! Its nice... My eyes are brown and if I had them blue I would love that!!