Hi,
Most schools don't even ask for your ACT scores. But in the case of MCO, they did. And like you, I had a low ACT score but a 340 OAT AA and 360 OAT TS. They asked me about my low ACT score and I just told them I hadn't studied for it and standardized tests weren't my forte.
So I wouldn't worry too much about it. The ACTs don't measure what you learned in college and don't relate much to optometry, but the OATs do.
Ning-Ju