I used to work in the colour contact industry back when I was in HS. Back then, it was only me, my coworkers, and some other girls on the street wearing "Beauty contact lenses". Basically, contact lenses that define the coloured bit of your eye. When the coloured part of your eye looks bigger you...
1) look younger (children have a bigger coloured bit of the eye compared to adults, making them look 'cuter')
2) your face looks slimmer (other attributes of your face seem smaller)
3) you tend to look better in photographs since your eyes are more defined
...benefits benefits benefits!
....These benefits are appealing and amazing to me, but now those contact manufacturers are going a little overboard. They make 2mm diameter contact lenses. Yup, you see some girls who look like ALIENS cause their iris is so big.
So when purchasing "define" contacts, make sure you try them on first to see if they fit you, and make sure you don't buy one which defines the coloured bit of your eye too much!
If you want to give it a try, but don't want something so intense like the picture above, I strongly recommend Acuvue's Define Series. It's a safe bet! :) You can purchase them here: Contact Lens Exchange (For US/Japan/Korean/Chinese buyers)
If you are a step ahead and are looking for Japanese colour/design/extreme/define contacts which look like the picture above go here! This company delivers to the US for only $15(USD) charge, great service as well. When I ordered, the contacts came in only 2 DAYS....They also sent me 2 packs of contact solution for free :) : 007 Contact Lenses
Personally, I do not like the contacts that Japan manufactures since they do not look "natural". Being Japanese with boring brown eyes, I've always wanted beautiful green or blue eyes. When wearing colour contacts, I want them to look as natural as it could be! I want people to ask me "Huh? Are they your real eyes?" , not "Oh, wow your lenses look cool". Through experience, I've found that the Freshlook colour contacts (especially the colour blended series) are the most natural looking, beautiful colour contacts that I have ever purchased. I love them! Go here to go to their website: http://www.freshlookcontacts.com/
I strongly recommend Green and Hazel for people with dark brown eyes like me! :) Hope it helps for those of you looking for lenses! Ask me any questions!