How Many Questions Is the ABO Exam?
The ABO basic exam — officially the National Opticianry Competency Examination (NOCE) — has 125 multiple-choice questions. Only 100 of them count toward your score; the other 25 are unscored pretest items that ABO-NCLE is trying out for future exams. You get 2 hours to finish.
That's the short answer. The rest of this guide covers the details that actually change how you prepare: the scored-versus-unscored split, pacing, how the scaled passing score works, what each domain is worth, and what happens if you don't pass.
125 questions, but only 100 count
The exam contains 125 multiple-choice questions. Of those, 100 are scored and 25 are unscored pretest items — new questions ABO-NCLE is evaluating before adding them to future exam forms. Your pass/fail result comes entirely from the 100 scored questions.
There is no way to tell which questions are pretest items while you're testing. They look identical to scored questions and are mixed throughout the exam. The practical takeaway: answer all 125 as if they count, because you'll never know which 25 don't.
You get 2 hours
The time limit is 2 hours, which works out to just under a minute per question across all 125.
In practice, pacing is uneven. Recall questions — anatomy terms, frame materials, ANSI standards — take ten seconds. Optics math like transposition, Prentice's rule, and vertex compensation takes two or three minutes if you're rusty. The candidates who run out of time are usually the ones grinding through formula work slowly, not the ones who don't know the material. Drill the math until it's fast; the optical calculators here are handy for checking your hand work while you practice.
Computer-based, four testing windows a year
The exam is computer-based, delivered at more than 300 Prometric test centers or from home through ProProctor remote proctoring. It runs in four quarterly windows: January–March, April–June, July–September, and October–December, with registration opening in the weeks before each window.
As of the February 2025 exam handbook, the registration fee is $225 and is non-refundable, and changing your exam date, time, or location costs $75 per change. Fees and dates get updated periodically, so confirm the current numbers on abo-ncle.org before you register.
What the 100 scored questions cover
The exam handbook publishes a content outline with six domains. The approximate weights of the scored questions: Ophthalmic Optics 25%, Ocular Anatomy/Physiology/Pathology and Refraction 10%, Ophthalmic Products 20%, Instrumentation 15%, Dispensing Procedures 20%, and Laws, Regulations, and Standards 10%.
Notice where the weight sits. Optics, products, and dispensing together account for 65 of the 100 scored questions. If your study time is limited, that's where it should go. The free study guides here are organized by category, so you can hit the heavy domains first instead of reading front to back.
The passing score is a scaled 70 — and that's not 70%
ABO-NCLE doesn't pass or fail candidates on a flat percentage. The passing standard is set with the Modified Angoff method — panels of subject-matter experts rate the difficulty of every question — and your raw score is converted to a scaled score. A scaled score of 70 is required to pass.
Because a harder exam form needs slightly fewer raw correct answers to reach the same scaled 70, the exact number of questions you need right varies from form to form. Don't try to game the cut score. If you're consistently scoring well above 70% on realistic practice tests, you're in good shape; if you're hovering at the line, you're not ready yet.
If you fail: the retake rules
You can retake the exam 14 days after the date you tested. You get three attempts on that cycle; after a third unsuccessful attempt, you must wait 90 days before testing again. Every attempt means registering again and paying the full exam fee — there's no discounted retake, and fees are non-refundable.
At $225 per attempt, failing is expensive. Fourteen days is enough time to patch one or two weak domains, but not to relearn optics from scratch — which is a good argument for not booking the exam until your practice scores say you're ready.
Practice in the real format before test day
The best predictor of how test day feels is whether you've already done it under the same constraints. ABO Test Prep's free ABO practice test gives you one full mock test every day at no cost, with questions drawn from all eleven categories in proportions matching the NOCE domain distribution.
Paid plans add an exam simulation mode that mirrors the real thing — 100 questions, a 2-hour countdown, and no explanations until you finish. Sit through that a few times and the clock on exam day is a familiar presence instead of a new stressor.
Frequently asked questions
How many questions are on the ABO exam?
The ABO basic exam (NOCE) has 125 multiple-choice questions. Only 100 are scored; the other 25 are unscored pretest items being evaluated for future exams, and they are indistinguishable from scored questions during the test, so answer every question as if it counts.
How long is the ABO exam?
You get 2 hours to complete all 125 questions — just under one minute per question. The exam is computer-based, taken at a Prometric test center or remotely through ProProctor proctoring.
What score do you need to pass the ABO exam?
A scaled score of 70 is required to pass. That is not the same as answering 70% of questions correctly — ABO-NCLE sets the passing standard with the Modified Angoff method and converts raw scores to a scale, so the exact number of correct answers needed varies slightly by exam form.
What happens if you fail the ABO exam?
You can retake the exam 14 days after your test date. After a third unsuccessful attempt, you must wait 90 days before testing again. Each attempt requires re-registering and paying the full exam fee, which is non-refundable.
When can you take the ABO exam?
The ABO basic exam is offered in four quarterly testing windows each year — January–March, April–June, July–September, and October–December — at more than 300 Prometric test centers or via ProProctor remote testing. Registration opens on abo-ncle.org in the weeks before each window.
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