I wanted to lay out a few ways that you can become a COA.
1. 1,000 hours of work Experience + JCAT + COA Exam
This is the most common way to become a COA. You have to work for an ophthalmologist for 1,000 hours (6 months full time) and pass the exam. You will also have to be sponsored by a doctor before you can set a test date. The cost is $300 for the initial exam, $250 for the first retake if you fail, and $150 for the third retake.
2. 1,000 hours of work Experience + (AAO) American Academy of Ophthalmology Independent study course + COA Exam
This is an alternative to the JCAT test. You will still have to pass a test, but it is written by the American Academy of Ophthalmology not JCAT. Though this is a way to become a COA it is important to see if you work place has a preferred option.
Even if you decide not to test with the AAO they have an outstanding text.
3. Accredited formal training programs
Formal Training programs are more common if you want to become a COT or a COMT. There are some programs that offer COA training, but most COAs just work under an ophthalmologist.
Check out my New Study Guide Study For the Certified Ophthalmic Assistant Exam