Qualifications
The main qualification you need to get into orthoptist training is a bachelor's degree from a regionally accredited college or university. And, yes, a science degree is preferred, but not required. Then it's on to one of thirteen orthoptist programs scattered across the U.S. for an intense study and hands-on learning program that costs from $2,000 to $5,000 to complete (source). Programs, like ones at the University of Michigan or the University of Iowa, put orthoptists on the fast-track to better things.
After your degree is earned, you go on to train for two years, then take a final test for certification. Once passed, you are fully licensed and can add the letters "C. O." (for certified orthoptist) to the end of your name. That's it. That's all you need. Well, that and a desire to actually do the job, but otherwise, it's a fairly easy process that yields a pretty high return.