The Optometry Admission Test (OAT) is administered by the American Dental Association's (ADA) Department of Testing Services on behalf of the Association of Schools and Colleges of Optometry (ASCO), and it's required for admission to every optometry school in the U.S. It's a sibling exam to the DAT -- same administering body, similar computer-based format at Prometric testing centers -- but don't assume the two are interchangeable: the sections, scoring scale, and science emphasis all differ in real ways.
The basic format
The OAT has four sections, and unlike the DAT, all four are covered by this site's practice question bank -- the OAT has no separate spatial/image-based section comparable to the DAT's Perceptual Ability Test. The sections are Survey of the Natural Sciences (100 questions, 90 minutes), Reading Comprehension (50 questions, 60 minutes), Physics (40 questions, 50 minutes), and Quantitative Reasoning (40 questions, 45 minutes) -- 230 questions and 245 minutes altogether.
Related: 6 Common OAT Mistakes -- and How to Avoid Them
What each section actually covers
- Survey of the Natural Sciences -- the largest section, split into Biology (40 questions), General Chemistry (30 questions), and Organic Chemistry (30 questions), covering essentially the same topic breadth as the DAT's version of this section -- cell/molecular biology, diversity of life, organ systems, genetics, and evolution/ecology for Biology; the standard general and organic chemistry curriculum for the other two.
- Reading Comprehension -- dense science passages tested for comprehension under time pressure, the same format and skill the DAT's Reading Comprehension section tests.
- Physics -- a section the DAT doesn't have at all. Algebra-based (non-calculus) introductory physics: kinematics, dynamics, energy and momentum, circuits, electrostatics, fluids, optics, rotational motion, simple harmonic motion, statics, thermodynamics, units, and waves.
- Quantitative Reasoning -- algebra, data analysis and interpretation, quantitative comparison, probability and statistics, and applied word problems. Unlike the CLT, a calculator is provided for this section on the real exam.
Understanding your score
The OAT has no pass/fail threshold. Each section is reported on its own scaled score of 200-400 -- a different scale from the DAT's 200-600 system, so don't assume a "good DAT score" and a "good OAT score" look the same numerically even though the two exams share an administering body. As with the DAT, optometry schools set their own admissions standards and generally look at your individual section scores rather than one fixed universal cutoff.
How to prepare
The real exam weights Survey of the Natural Sciences most heavily (roughly 43%), followed by Reading Comprehension (22%), Quantitative Reasoning (18%), and Physics (17%) -- so science content should still get the largest share of your study time, but Physics deserves genuine, dedicated attention rather than being treated as an afterthought, since it's a full section worth nearly a fifth of the exam and one many pre-optometry students haven't touched since an intro physics course. Within Survey of the Natural Sciences, Biology carries the single largest share, same as on the DAT. Start with a baseline practice exam before committing to a study plan, and weight your review time to match these real proportions rather than spreading effort evenly across every topic.
Test day
Like the DAT, the OAT is administered essentially year-round at Prometric testing centers rather than on fixed national dates, which gives you real flexibility in scheduling -- but you'll still need to complete your application through ADA and then book your specific appointment through Prometric well ahead of your target date. Bring valid, government-issued photo ID that matches your application exactly, and check ADA's current OAT program page directly for up-to-date application deadlines and retake policies before you plan your testing timeline.