International students can register for and take the OAT -- but, like its sibling exam the DAT, there are real, specific limitations worth understanding before you plan around it, especially around where the test is actually offered and what optometry school admission itself requires beyond a strong score.
Where the OAT is actually administered
This is the single most important fact for anyone testing from outside North America: the OAT, like the DAT, is administered at Prometric test centers in the United States and at select locations in Canada -- but it is no longer offered in the province of Quebec. There is no broader international testing network the way there is for the ACT -- if you live outside the U.S. or Canada, you'll need to travel to one of these locations to sit for the exam.
Related: What to Expect on the OAT: Format, Scoring, and How to Prepare
What registration requires
Registration for the OAT is managed through ADA's Department of Testing Services, the same body that administers the DAT, and requires valid identification along with the standard application process outlined in the OAT Candidate Guide. Note that fee-waiver eligibility for the OAT requires U.S. citizenship or resident-alien status -- international students testing on a student visa or from abroad generally will not qualify for a fee waiver.
The OAT is only one part of a much bigger hurdle
Passing the OAT with a strong score does not by itself guarantee admission eligibility -- optometry school admission requirements for international applicants vary significantly by school and by country. In Canada, for example, the University of Waterloo's optometry program generally requires Canadian citizenship or at least twelve months of legal residency in Canada prior to the start of the program, though it notes that international students on a study visa may be considered in limited, special circumstances. In the United States, international applicants are generally expected to meet the same academic requirements as domestic applicants, while also demonstrating sufficient financial resources and English-language proficiency to succeed in the program.
What to do before investing in OAT prep
Because optometry school eligibility for international applicants varies so much by specific school, research the actual admission requirements at your target schools before committing significant time and cost to OAT preparation -- a strong OAT score is necessary but not sufficient at many programs if you don't otherwise meet a school's citizenship, residency, or financial requirements. Contact your target schools' admissions offices directly, since these policies can vary meaningfully between otherwise similar programs and can change from year to year.
The bottom line
If you're an international student seriously considering U.S. or Canadian optometry school, plan your OAT test date around travel to an eligible Prometric location well in advance, and confirm your specific target schools' international-applicant policies early -- ideally before you begin serious test prep, not after.