I think you should do both, study hard for the OAT and then try to find a job working for an optometrist. I think these two are some of the most important requirement that optometry schools look at. Plus when you work for an optometrist, during the interview you have more to say and it would seem like you know what you're talking about. you also meet others that have the same interest as you and you could help each other out. It's cool...... 🙄