COA study guide
COA · Work through your exam, one topic at a time.
The Certified Ophthalmic Assistant (COA) is an entry-level credential for allied health personnel working in ophthalmology practices, issued by the International Joint Commission on Allied Health Personnel in Ophthalmology (IJCAHPO). It is intended for ophthalmic assistants who perform routine patient care tasks under supervision and who want formal recognition of foundational competency. The COA study guide has 6 sections and about 1,730 words.
01Clinical Optics and Basic Ophthalmic Optics
A candidate must be fluent with the vergence formula, the thin-lens equation, and the relationship between focal length and power in diopters (D = 1/f in meters). Know how light refracts at each ocular surface, the reduced eye model, and why the cornea provides roughly two-thirds of the eye's refractive power while the crystalline lens provides the rest and adds accommodation.
342 words, about 2 min02Basic Ocular Anatomy and Physiology
Master the layered structure of the eye: the fibrous tunic (cornea and sclera), vascular tunic (iris, ciliary body, choroid), and neural tunic (retina). Know the flow of aqueous humor from the ciliary body through the posterior chamber, pupil, and anterior chamber to the trabecular meshwork and canal of Schlemm.
289 words, about 1 min03Ocular Pharmacology and Medication Instillation
Know drug classes and their mechanisms: mydriatics and cycloplegics (anticholinergics like tropicamide and atropine vs. sympathomimetics like phenylephrine), topical anesthetics, anti-infectives, anti-inflammatories (steroids and NSAIDs), and glaucoma agents (beta-blockers, prostaglandin analogs, alpha agonists, carbonic anhydrase inhibitors, cholinergic agonists).
265 words, about 1 min04Patient History, Visual Acuity, and Basic Testing
A structured history captures chief complaint, ocular and medical history, medications, allergies, family history, and social history, then the classic symptom descriptors: onset, duration, laterality, severity, and associated symptoms. For visual acuity, know Snellen notation, the 20/20 reference, the meaning of the numerator (test distance) and denominator (distance at which a normal eye sees that line), and when to use pinhole (to distinguish refractive from pathology-related loss).
302 words, about 2 min05Patient Preparation, Instrumentation, and Assisting with Procedures
Understand room and instrument setup, patient positioning, and the assistant's role in procedures such as slit-lamp exams, tonometry, dilation, foreign-body removal, and minor surgery. Know the purpose and basic operation of common instruments: slit lamp, ophthalmoscope, retinoscope, keratometer, tonometer, autorefractor, and perimetry.
281 words, about 1 min06Infection Control, Safety, and Professional/Administrative Duties
Understand standard precautions: hand hygiene as the single most important measure, use of gloves and personal protective equipment, safe handling and disposal of sharps, and disinfection versus sterilization. Know the difference-disinfection reduces pathogens on surfaces and instruments, sterilization eliminates all microorganisms including spores.
251 words, about 1 min