I have the red ones! I got em like, last year ^.^
Be careful, they rip very easily (I need to get new ones now -_-)
And also, contacts naturally rotate, so make sure you're okay with the slits randomly going diagonal and horizontal. If you don't like that idea try finding weighted ones or "Vampires", which are red and just don't have the cat slit in them.
Once I find my old Catgirls IRL thread I'll link you to the page with the pic of my kitty eye on it ^.^
Edit: I found it!
Catgirls IRL (page 23), right there!!
It's a great thread, I say we bring it back to life!