OHHHHHHHHHH, ok yeah you need to google doll eye, maybe even check with a Taxidermy place to make the one just like Oobies. When I went to the muppet audition they had 2 Pin pong balls attached together with some elastic, and they looked really nice.
The peepers that Buck Mention are cool I use to keep them in my pocket if I ever came need a puppet on the fly. the only draw back (to me) is that they pinched so tight that they hurt my hand. I'm not a wimp, they were just anoying!