OAT Study Guide for Optometry School: Sections, Scoring, and How to Prepare
If you're aiming for optometry school, the Optometry Admission Test (OAT) is the one gatekeeper standing between you and an admissions committee actually looking at your application. It's not the most famous standardized test out there — most people have heard of the MCAT, fewer have heard of the OAT — but it carries just as much weight for the ~20 optometry programs in the U.S. and select Canadian schools that require it.
This guide walks through exactly what's on the OAT, how it's scored, what it costs right now, and how to build a study plan that doesn't leave you cramming organic chemistry reactions the night before your test date.
What Is the OAT, Exactly?
The OAT is a computer-based, multiple-choice exam administered by the American Dental Association (ADA) on behalf of the Association of Schools and Colleges of Optometry (ASCO). Yes — the same organization that runs the Dental Admission Test (DAT) also runs the OAT. That's not a coincidence, and it's part of why so many students get the two mixed up (more on that below).
The OAT is designed to measure whether you have the science foundation, reading comprehension, and quantitative reasoning skills to survive the first year of optometry school. It's offered year-round at Prometric testing centers, so you're not locked into a handful of national test dates the way you are with some other exams.
Most successful applicants complete at least one full year of college coursework before sitting for the OAT, and the majority wait until they've finished two or more years — largely because you need general chemistry and organic chemistry under your belt before the science section makes any sense.
OAT Section-by-Section Breakdown
The OAT has four scored sections and 230 total multiple-choice questions. Here's the official breakdown:
| Section | Content Covered | Questions | Time |
|---|---|---|---|
| Survey of Natural Sciences | Biology (40), General Chemistry (30), Organic Chemistry (30) | 100 | 90 minutes |
| Reading Comprehension | 3 passages on scientific topics | 40 | 50 minutes |
| Physics | Mechanics, waves, electricity, optics, and more | 40 | 50 minutes |
| Quantitative Reasoning | Algebra, applied math, data interpretation | 40 | 45 minutes |
That's 235 minutes (just under 4 hours) of actual testing. Your total seat time runs longer — around 4 hours 50 minutes — because the appointment also includes an optional 15-minute pre-test tutorial, a 30-minute break (usually placed after the Survey of Natural Sciences), and a 15-minute post-test survey.
One thing worth flagging early: unlike the DAT, the OAT does not include a Perceptual Ability Test (spatial reasoning with 3D shapes and mirror images). If you've heard predental friends complain about "PAT," that's a DAT-only section — it has no equivalent on the OAT.
How the OAT Is Scored
This is where a lot of confusion creeps in, so let's be precise. The OAT reports standard scores on a 200 to 400 scale, in increments of 10. The national average sits right around 300, which represents roughly the 50th percentile of examinees — so a 300 is an average score, not a bad one, despite "300 out of 400" sounding low if you're mentally comparing it to a percentage grade.
Your official score report actually contains eight numbers, not four:
- Biology
- General Chemistry
- Organic Chemistry
- Physics
- Reading Comprehension
- Quantitative Reasoning
- Total Science — a composite converted from your combined Biology, General Chemistry, Organic Chemistry, and Physics performance
- Academic Average (AA) — the average of your six individual section scaled scores, and the number optometry schools tend to lean on most heavily as a single snapshot
An unofficial score report (covering everything except, in some cycles, the essay-adjacent components) is available at the test center the moment you finish. Official scores are released to your designated schools within roughly three to four weeks and posted to your OAT PIN account.
OAT Fees and Registration
As of the 2025-2026 testing cycle, the OAT registration fee is $510 for testing within the U.S., Canada, and U.S. territories, and $619 for international testing locations. Partial fee waivers covering 50% of the cost are sometimes available on a first-come, first-served basis for candidates who demonstrate financial need — but they're limited, and in past cycles they've been claimed before the year is out, so apply early if you think you'll qualify.
Additional charges apply for things like rescheduling, additional score reports beyond what's included, and score reviews, so budget a little extra beyond the base fee.
Retake Policy: What Happens If You Don't Like Your Score
You can retake the OAT, but not on your own schedule. Per current ADA policy:
- You must wait 60 days between testing attempts.
- You're capped at four attempts in any 12-month period.
- After your third attempt, you need permission to test again, along with proof that you've recently applied to an optometry program.
- After your fifth attempt, you can only retest once every 12 months.
Because scores from your most recent attempts are all visible to the schools you send them to, retaking the OAT isn't a clean slate — admissions committees will see the trend line, not just your best score. That's a strong argument for treating your first attempt as your real attempt rather than a "practice run."
The Biggest Misconception About the OAT
"I figured I'd just study for the MCAT since it's basically the same test, right?" — a version of the question pre-optometry advisors hear constantly.
Here's the misconception, in two parts:
OAT vs. MCAT: These are not interchangeable exams, and studying MCAT materials wastes real time. The MCAT devotes an entire section (CARS) to humanities and social-science passages with zero science content, plus a full section on psychology and sociology — none of which appears on the OAT at all. The OAT, by contrast, leans much harder into organic chemistry and physics content packed into a shorter overall test.
OAT vs. DAT: This mix-up is more understandable, since the ADA administers both exams and the science content overlaps heavily (Biology, General Chemistry, Organic Chemistry are tested almost identically on paper). But the two tests have diverged further recently: in March 2025, the DAT switched from its old 1-30 scoring scale to a new 200-600 scale, while the OAT has stayed on its 200-400 scale. If you're using an old article, a DAT prep book, or a friend's advice from a few years ago, double-check which scale and which test you're actually looking at — a "290" means something very different depending on which exam produced it. The DAT also includes the Perceptual Ability Test section described above, which simply doesn't exist on the OAT.
Bottom line on misconceptions: treat the OAT as its own exam with its own syllabus, its own scale, and its own timeline — not a stand-in for whatever your premed or predental friends are studying.
OAT vs. DAT vs. MCAT: Quick Comparison
| OAT | DAT | MCAT | |
|---|---|---|---|
| Administered by | ADA (for ASCO) | ADA | AAMC |
| Sections | 4 (Natural Sciences, Reading Comp, Physics, Quant Reasoning) | 4 (Natural Sciences, Perceptual Ability, Reading Comp, Quant Reasoning) | 4 (Chem/Phys, CARS, Bio/Biochem, Psych/Soc) |
| Total questions | 230 | 280 | 230 |
| Approx. testing time | ~3 hrs 55 min | ~4 hrs 15 min | ~6 hrs 15 min |
| Scoring scale | 200-400 (10-pt increments) | 200-600 (as of March 2025) | 472-528 |
| Average/50th percentile | ~300 | ~400 | ~500 |
| Current fee (2025-2026) | $510 (US) / $619 (intl) | ~$560 | ~$355 standard / $145 with fee assistance |
| Unique section | None beyond core 4 | Perceptual Ability Test | CARS (no science content) |
Figures on fees and scales can shift year to year, so always confirm current numbers on oat.ada.org, ada.org, and aamc.org before you register.
How to Prepare: A Realistic Study Timeline
Most successful OAT takers put in somewhere between 200 and 400 hours of dedicated study spread across 3 to 6 months, not counting the coursework they've already absorbed in class. Here's a reasonable structure:
- Months 1-2 — Content review. Work systematically through Biology, General Chemistry, and Organic Chemistry using a dedicated OAT prep book or course rather than your old class notes, since the OAT emphasizes breadth and speed over depth. Physics gets folded in here too if it's been a while since you took it.
- Month 3 — Quantitative Reasoning and Reading Comprehension. These sections reward strategy as much as raw content knowledge — timing drills and passage-reading techniques matter more here than memorization.
- Final 4-6 weeks — Full-length practice tests. Simulate real test-day conditions: same time of day, same section order, same 30-minute break placement. Review every missed question and track which subsection (not just which section) is bleeding points.
- Final week — Light review only. Cramming new material this close to test day tends to hurt confidence more than it helps scores.
Because you can't take partial sections — the OAT requires you to sit for all four in one appointment — pacing across a nearly 4-hour test is itself a skill you need to practice, not just the content.
Bottom Line
The OAT is a four-section, 230-question exam scored on a 200-400 scale, administered by the ADA on behalf of optometry schools nationwide. It costs $510 to register (as of the 2025-2026 cycle), it's distinct from both the DAT and the MCAT despite surface similarities, and you get a maximum of four attempts per year with a mandatory 60-day gap between them. Treat it as its own test with its own content map — build a 3-to-6-month study plan anchored in Natural Sciences, Physics, Reading Comprehension, and Quantitative Reasoning, run full-length practice exams under real timing, and go into test day aiming to hit your target Academic Average on the first attempt rather than planning around a retake.
FAQ
Is the OAT harder than the MCAT? They're hard in different ways rather than one being objectively harder. The OAT packs more organic chemistry and physics into a shorter test, while the MCAT is longer overall and tests content the OAT doesn't touch, like CARS passages and psychology/sociology. Difficulty really comes down to your own strengths.
What is a good OAT score for optometry school? There's no single universal cutoff, since it varies by program, but an Academic Average in the mid-300s is generally considered competitive at most U.S. optometry schools, with top-tier programs often seeing accepted averages higher than that. Check each target school's published average incoming-class scores for the most accurate benchmark.
Can I take the OAT more than once? Yes, but with restrictions: a mandatory 60-day wait between attempts, a cap of four attempts per 12-month period, and additional permission requirements after your third and fifth attempts.
Do optometry schools see all my OAT attempts? Your score reports include your recent testing history, so schools generally see more than just your highest score. This is one reason to prepare thoroughly before your first attempt rather than treating it as a dry run.
Does the OAT include an essay or writing section? No. The OAT's four scored sections are Survey of Natural Sciences, Reading Comprehension, Physics, and Quantitative Reasoning — there is no writing sample section on the current exam.
How is the OAT different from the DAT if the same organization administers both? The core science content (Biology, General Chemistry, Organic Chemistry) is similar, but the DAT adds a Perceptual Ability Test that the OAT doesn't have, and as of March 2025 the two exams use different scoring scales entirely — the DAT moved to 200-600 while the OAT remains on 200-400.
