I asked on the twins eyes page and here was there response:
Hello?
The eyes in one pairs will be sent if you choose one in QTY option.
Instead of, twin eyes has a double iris per an eyes.
So, you can choose 4 different kinds of colors for it if you want.
Contact us if you have any questions.
Thank you.
yay for engrish! lol, but it will get my mom off my back ^^