What Is A CO?

The Short Answer: A CO Is a Certified Orthoptist

In this context, a CO is a Certified Orthoptist: an eye care professional who has completed accredited orthoptic training and earned certification through the American Orthoptic Council. Orthoptists specialize in the evaluation and nonsurgical management of eye movement and alignment problems, with particular attention to binocular vision, strabismus, and related ocular motor disorders.

If you are looking for a broader definition of the abbreviation itself, our companion pages on what CO stands for and what CO certification is cover the naming and credential basics. This article focuses on what the role is, how someone becomes a CO, and what the training expects you to know.

What an Orthoptist Actually Does

Orthoptists sit at the intersection of diagnostics, patient education, and nonsurgical treatment. Their daily work typically involves patients whose two eyes do not work together comfortably, from young children with misaligned eyes to adults with double vision after neurological events or systemic disease.

The published subject areas of orthoptic training give a clear picture of the work:

• Measuring and documenting eye alignment and movement using clinical diagnostic techniques.
• Applying nonsurgical treatment, both theoretical and clinical, for binocular and ocular motor problems.
• Supporting surgical care through pre- and postoperative assessment around alignment and eye-movement surgery performed by ophthalmologists.
• Working with patients across age groups, which is why child development appears in the training content alongside systemic disease.

Because the work spans optics, neurology, pharmacology, and pediatrics, the credential rewards breadth. Candidates who treat it as a narrow technician certification tend to be surprised by the amount of underlying science.

Who Certifies Orthoptists

Two organizations are easy to confuse, so it helps to separate them clearly.

When you see a candidate described as board certified in orthoptics, the AOC is the body behind that status. The AOC continues to recognize newly certified orthoptists on its current home page, which supports the view that the credential is active and currently awarded.

The Path to the Credential

The route to becoming a Certified Orthoptist is a training pathway followed by examination, not a stand-alone test you can sit after self-study. For the detailed eligibility picture, see our CO requirements guide; the essentials are below.

Accredited Training

The published standard training program is 24 months. It combines didactic instruction with clinical training across different age groups, delivered under a certified orthoptist or an ophthalmologist. Admission normally requires a bachelor's degree, and individual programs may set their own prerequisites on top of that.

Advanced Standing

Some applicants hold related credentials. Qualifying COT or COMT holders with an undergraduate degree may be considered for advanced standing. This is not automatic: it requires at least 12 months in an accredited program, plus program-director approval and a readiness review.

Written and Oral Board Examinations

According to the AOC, accredited orthoptic training is followed by written and oral board certification examinations. The oral component matters: it means the credential assesses clinical reasoning and skill that a written question bank cannot fully reproduce. The AOC publications page also states that the 2024 Syllabus of Orthoptic Instruction and Core Competencies: Essential Skills for Orthoptists form the basis of the certifying examinations. The first addresses didactic information and the second clinical skills.

Cost Considerations

Tuition is set by individual training programs, so there is no single universal fee that applies everywhere. The two AOC publications mentioned above carry published prices of $150 and $35, but those are document prices, not examination fees. For a fuller discussion of what to budget, see our CO certification cost breakdown.

International Applicants

International eligibility is evaluated separately by the AOC. Do not assume that credentials or training from another country transfer automatically.

The Eleven Subjects Behind the Training

The AOC's Become an Orthoptist page describes the subjects covered in the fellowship course. These eleven headings are the clearest public map of what a candidate must learn. They are training subjects, not officially weighted exam domains, and the AOC has not published percentage weights for them. Our complete guide to the CO content areas goes deeper on each one.

What We Know and Don't Know About the Examination

Honest preparation starts with separating verified facts from assumptions. The AOC publicly confirms that written and oral board examinations follow accredited training, and that the 2024 syllabus and core competencies documents form the basis of those examinations. Several details are not confirmed in the public sources reviewed:

• The current written item format and question count.
• The time limit for any written component.
• A numerical passing threshold.
• The split between scored and unscored items.
• An actual published pass rate.
• Current examination booking fees and the exact renewal cycle and fees.

It is also worth being clear about what a practice question bank is. Practice questions here are an editorial tool for supplemental written-knowledge review. Their format should not be read as a description of the live examination, and they do not replace supervised clinical education, oral or practical skill assessment, or professional judgment. For a realistic read on difficulty, see how hard the CO exam is.

Scope of Practice and Clinical Context

A Certified Orthoptist works within a supervising clinical context, typically alongside ophthalmologists. The credential recognizes specialized competence in orthoptic evaluation and nonsurgical management; it is not independent physician authority and does not confer prescribing authority.

This matters for how scenarios are reasoned through. A well-prepared candidate recognizes when a finding calls for communication with the supervising ophthalmologist, when a presentation suggests a systemic or neurological cause needing medical evaluation, and when surgical consultation is the appropriate pathway. The Principles of Surgery subject reflects this directly: the orthoptist supports pre- and postoperative care for surgery that ophthalmologists perform.

Where Certified Orthoptists Work

Because training takes place under certified orthoptists or ophthalmologists, the profession is closely tied to ophthalmology practices and eye care teams. Typical environments include ophthalmology offices, pediatric eye care settings, and academic or teaching-hospital eye departments, where the combination of children, adults, and complex ocular motor cases is most common.

Specific employer lists and earnings vary and are not published in the AOC sources reviewed, so this article does not quote figures. If you are weighing the career, our pages on CO jobs, the CO salary guide, and whether the CO certification is worth it discuss the decision in more depth.

After certification, continuing education is required to maintain it. The exact current renewal cycle and fees were not verified, so confirm them directly with the AOC.

Not Every "CO" Is This CO

The letters CO are shared by several unrelated professional credentials and job titles. Certified Orthoptist is not the same as an orientation and mobility specialist, an ophthalmic executive, an orthopaedic surgery coder, or an optometrist or ophthalmologist. It also has nothing to do with the licensing pathways for those professions.

This is more than a naming quibble. Fees, certifying bodies, schedules, and content differ completely between credentials that happen to share an abbreviation. When you research, always confirm that the source is talking about the American Orthoptic Council and orthoptics before you rely on any detail. Related explainers like what CO means and CO meaning help you anchor on the right definition.

Scheduling Your Preparation Around the Subjects

Since official weights are unpublished, a sensible plan sequences the subjects by dependency: foundations first, applied clinical reasoning later. The sample below treats the eleven subjects as a build-up rather than a ranking. It supplements, and never replaces, your supervised training and the AOC's own syllabus documents. For a fuller plan, see our CO study guide.

Frequently Asked Questions