FREE COT Study Guide 2026: A Complete IJCAHPO Walkthrough

This free COT study guide walks through the highest-yield content the IJCAHPO Certified Ophthalmic Technician (COT) exam tests, organized by the five official categories of the COT examination content outline — Assessments, Assisting with Interventions & Procedures, Imaging, Office Responsibilities, and Corrective Lenses.^[1]

It is interactive, not a wall of text: every category has worked clinical scenarios, data tables, labeled diagrams, and built-in flashcards, taught the way the COT is actually tested — the anatomy and assessments behind visual acuity, retinoscopy, tonometry, biometry, and the seven hands-on Skill Evaluation stations.

Read it module by module, then round out your prep with our practice questions and flashcards. The COT is the mid-level credential in IJCAHPO’s COA → COT → COMT ladder, so this guide assumes the assistant-level basics and teaches up to technician-level skills.

COT Exam Snapshot

Assessments is by far the largest category at 45% of the written exam.Assisting with Interventions & Procedures is 17%, Imaging is 15%, Office Responsibilities is 14%, and Corrective Lenses is 9%. Six of the seven Skill Evaluation stations — lensometry, visual fields, ocular motility, keratometry, retinoscopy, and refinement — plus applanation tonometry sit inside the Assessments content, so mastering it prepares you for both parts of the exam.^[1]

Percentages are each category’s share of the 200 scored written items.^[1] This guide teaches all five categories as eight study modules — the 45% Assessments category is split across four modules so each assessment skill gets full teaching depth, with the official category mapping noted in each section.

How the COT Exam Is Built

The COT credential has two parts, and you must pass both. First is a 200-question written (multiple-choice) exam built from the IJCAHPO content outline. Then, after passing the written exam, you take a computer-simulated Skill Evaluation of seven hands-on stations.^[1]

• Assessments (45%) — history and documentation, visual acuity, visual fields, pupils, tonometry, keratometry, ocular motility, lensometry, retinoscopy and refinement, biometry, and supplemental testing: the clinical core of the job.
• Assisting with Interventions & Procedures (17%) — microbiology and sterilization, pharmacology, surgical assisting, and ophthalmic patient services and education.
• Imaging (15%) — ophthalmic imaging (OCT, angiography, A/B-scan, topography) and photography and videography.
• Office Responsibilities (14%) — equipment maintenance and calibration, medical ethics and legal/regulatory issues, communication, and administrative duties.
• Corrective Lenses (9%) — optics and spectacles and contact lenses.

The seven Skill Evaluation stations are lensometry, visual fields, ocular motility, keratometry, retinoscopy, refinement, and applanation tonometry — each scored on technique and accuracy, with all seven required to pass. Notice the overlap: every one of those skills also lives in the written Assessments category, so the study modules below prepare you for both.^[1]

Ocular Anatomy & Patient History

This module covers the foundation every other COT skill rests on: the anatomy and physiology of the eye (part of Patient Services & Education) and History and Documentation (part of the 45% Assessments category).^[1] You cannot interpret an acuity, an IOP, or a refraction without knowing the structures behind them.

Anatomy of the Eye

The eye has three layers. The outer fibrous coat is the cornea (clear, front) and the sclera (white wall). The middle vascular uvea is the iris, ciliary body, and choroid. The inner neural retina captures light and sends it through the optic nerve.

Light is focused chiefly by the cornea (about two-thirds of the eye’s power) and fine-tuned by the crystalline lens. It lands on the macula, whose center, the fovea, gives the sharpest vision; the optic disc where the nerve exits is the physiologic blind spot.^[3]

The Cornea & Tear Film

The cornea has five layersfrom front to back: epithelium, Bowman’s layer, stroma, Descemet’s membrane, and endothelium. The endothelium is a single, non-regenerating cell layer that pumps fluid out to keep the cornea clear — losing those cells causes corneal swelling and haze.

Sitting on top is the three-layer tear film— an outer lipid layer (meibomian glands), a middle aqueous layer (lacrimal gland), and an inner mucin layer (goblet cells) — which is actually the eye’s first refractive surface and keeps the cornea smooth.^[4]

Aqueous Humor & Refractive Errors

The ciliary body produces aqueous humor, which flows from behind the iris, through the pupil, and drains at the angle through the trabecular meshwork into Schlemm’s canal. When that drain resists, IOP rises — the basis of glaucoma.

Refraction depends on the eye’s length and power. In emmetropia light focuses on the retina; in myopia it focuses in front (minus lens corrects); in hyperopia behind (plus lens); astigmatism focuses at two points (cylinder); and presbyopia is the age-related loss of accommodation.^[3]

History Taking & Documentation

A COT-level history covers ocular, medical, medication, social, and familyhistory, starting from the chief complaint in the patient’s own words. A structured symptom history (onset, location, duration, character, aggravating/relieving factors, timing, severity) makes the record useful to the physician.

Ask about systemic medications — many affect the eye (steroids, tamsulosin, hydroxychloroquine, amiodarone) — and document drug allergies with the specific reaction. Use the standard abbreviations OD (right eye), OS (left eye), and OU (both eyes), and correct a paper error with a single line, “error,” the fix, and your dated initials.^[1]

Visual Assessment & Refractometry

This module gathers the assessment skills that measure and correct vision — Visual Assessment, Lensometry, Refractometry (Retinoscopy & Refinement) from the 45% Assessments category, plus Optics & Spectacles and Contact Lenses from the 9% Corrective Lenses category.^[1] Five of the seven Skill Evaluation stations live here.

Visual Acuity & Pinhole

Visual acuity is recorded as a Snellen fraction at 20 feet: in 20/40, the patient reads at 20 feet what a normal eye reads at 40 — worse than normal. Research uses the even-stepped logMAR (ETDRS) scale. When letters can’t be read, record Counting Fingers, Hand Motion, Light Perception, then No Light Perception with the distance.

The pinhole separates refractive error from pathology: if acuity improves through it, the patient simply needs a better prescription; if it doesn’t, suspect a media opacity or a retinal/optic-nerve cause.^[4]

Lensometry

Lensometry (focimetry) measures an existing spectacle lens — its sphere, cylinder, axis, prism, and bifocal add — by neutralizing it. To read a bifocal add, measure the distance power, then the segment power; the add equals the near power minus the distance power and is always plus.

On a manual lensometer, focus the eyepiece first, then move the power drum until the mires are sharp at each meridian. Lensometry is the first of the seven Skill Evaluation stations.^[1]

Retinoscopy & Refinement

Retinoscopy is an objective refraction: sweep a streak across the pupil and neutralize the reflex. “With” motion (reflex moves with the sweep) needs plus lenses; “against” motion needs minus; no movement is neutral. Because it needs no patient responses, it works for infants and non-verbal patients.

Refinement then fine-tunes the result subjectively: find the best sphere, refine the cylinder axis and power with the Jackson Cross Cylinder (“better one or two?”), re-balance the sphere, and check the endpoint with the red-green duochrome test. Retinoscopy and refinement are two more Skill Evaluation stations.^[4]

Optics, Prism & Transposition

A plus (convex) lens converges light and magnifies (hyperopia, presbyopia); a minus (concave) lens diverges and minifies (myopia). The spherical equivalent — sphere plus half the cylinder — is the single sphere that best represents a sphero-cylindrical lens.

Transposition rewrites a prescription between plus- and minus-cylinder forms: add the cylinder to the sphere, flip the cylinder sign, and rotate the axis 90 degrees (so +2.00 +1.00 × 090 becomes +3.00 −1.00 × 180). A prism diopter (Δ) displaces an image 1 cm at 1 meter, and high-power lenses must account for vertex distance.^[1]

Spectacles & Contact Lenses

A contact-lens fit is described by base curve, diameter, and power; the base curve is matched to the cornea’s keratometry. Keratoconus (a progressive corneal cone with irregular astigmatism) is best corrected with rigid gas-permeable or scleral lenses, and fluorescein shows the tear-film pattern under an RGP lens.

Contact lenses mold the cornea, so patients must remove them before keratometry, topography, or biometry. The most serious risk of overnight wear is microbial keratitis — a corneal infection (Pseudomonas, Acanthamoeba) that is a sight-threatening emergency.^[4]

Pupils, Motility & Visual Fields

Three more Assessments skills — Pupil Assessment, Ocular Motility Testing, and Visual Field Testing — that screen the neurological side of vision.^[1] Visual fields and ocular motility are two of the seven Skill Evaluation stations.

Pupil Assessment & RAPD

The pupil exam records PERRLA — Pupils Equal, Round, Reactive to Light and Accommodation — plus size in light and dark. Shining light in one eye constricts it (direct) and the fellow eye (consensual). Unequal pupils are anisocoria; whether the difference is greater in light or dark localizes the cause.

The COT-level skill is the RAPD (Marcus Gunn pupil): on the swinging-flashlight test, both pupils dilate when light reaches the affected eye, signaling optic-nerve or severe retinal disease.^[4]

Ocular Motility & Strabismus

Motility testing checks the six cardinal positions of gaze (each isolating a pair of yoke muscles) and the alignment of the eyes. A tropia is a manifest, constant deviation found on the cover-uncover test; a phoria is a latent deviation held by fusion and revealed by the alternate cover test.

Deviations are named by direction: esotropia (in), exotropia (out), and hypertropia (up). Prism cover testing measures the deviation in prism diopters, and the Hirschberg corneal light reflex estimates alignment by where a penlight reflects on each cornea. COT-level motility also includes near point of convergence, Worth 4-dot, and Maddox rod testing.^[1]

Visual Field Testing

Perimetry maps the field of vision. Confrontation fields are a bedside screen; automated (e.g., Humphrey) perimetry is static threshold testing; and Goldmann perimetry is kinetic (a moving target). A scotoma is an area of lost field.

Field defects localize disease: glaucoma causes nasal steps and arcuate scotomas; a bitemporal hemianopia points to the optic chiasm (e.g., pituitary tumor); a homonymous hemianopia points behind the chiasm. Watch the reliability indices (fixation losses, false positives/negatives) before trusting a field.^[4]

Tonometry, Keratometry & Biometry

The measurement-heavy Assessments skills — Tonometry, Keratometry, Biometry, and Supplemental Testing.^[1] Applanation tonometry and keratometry are two of the seven Skill Evaluation stations.

Tonometry & IOP

Tonometry measures intraocular pressure, normally about 10–21 mmHg. Goldmann applanation tonometry is the gold standard — it flattens a fixed corneal area, and the force needed equals the pressure. Instill a topical anesthetic and fluorescein, then align the mires.

Corneal thickness matters: thick corneas read falsely high and thin corneas falsely low, so pachymetry helps interpret the IOP. The applanation tip touches the cornea, so it is a semicritical item needing high-level disinfection or a disposable tip between patients.^[4]

Keratometry & Topography

Keratometry measures the central corneal curvature along its two principal meridians (the K readings) and the corneal astigmatism. Those readings are used to fit contact-lens base curves, calculate IOL power, and monitor keratoconus. Corneal topography maps the whole surface and better detects irregular astigmatism.^[4]

Biometry & IOL Power

Biometry measures the eye to calculate the intraocular lens power for cataract surgery, and axial length is the most influential value: a 1 mm error causes roughly 2.5–3 diopters of postoperative refractive error. Optical (IOLMaster) biometry is non-contact and most precise; ultrasound A-scan is used when dense media block the optics.

Within A-scan, applanation touches and can compress the cornea (falsely short), while immersion uses a saline standoff and avoids that error.^[4]

Supplemental Testing

Supplemental Testing rounds out the assessments: pachymetry (corneal thickness), anterior-chamber depth, glare and contrast testing, color vision (Ishihara), exophthalmometry (Hertel) for proptosis, and the tear tests — the Schirmer test (aqueous tear production) and the tear breakup time (tear-film stability; under 10 seconds suggests dry eye). Many of these are COT-level supplemental skills.^[1]

Ophthalmic Imaging & Photography

The Imagingcategory is 15% of the written exam, split into Ophthalmic Imaging (7%) and Photography & Videography (8%).^[1] It includes the diagnostic scans a COT performs and the clinical photographs that document disease.

OCT & Scanning Lasers

Optical coherence tomography (OCT) uses light interferometry to make cross-sections of the retina and optic nerve — no dye, no contact. For glaucoma it measures the retinal nerve fiber layer (RNFL) and ganglion cell thinning that precedes field loss; for the macula it shows edema and degeneration. Related scanning-laser tools (HRT, GDx) also map the optic nerve.^[4]

Angiography & Ultrasound

Fluorescein angiography injects dye and times retinal photos to show blood flow, leakage, and ischemia (diabetic retinopathy, macular degeneration). Expected effects are transient nausea and yellow-orange skin/urine; the key risk is rare anaphylaxis, so emergency drugs must be ready. Indocyanine green images the deeper choroid.

A B-scan ultrasound images the posterior eye when the view is blocked (dense cataract, vitreous hemorrhage) to find retinal detachment, tumors, or foreign bodies. Specular microscopy counts corneal endothelial cells before surgery.^[4]

Photography & Videography

Slit-lamp (anterior segment), fundus, and external photography document and monitor disease over time. A good clinical photo has sharp focus, correct exposure, proper centration of the pathology, and accurate labeling — every image must carry the patient ID, date, and which eye (OD/OS). Mislabeling an eye is a serious, avoidable error.^[1]

Pharmacology, Microbiology & Instruments

From the Assisting category come Pharmacology and Microbiology, and from Office Responsibilities comes Equipment Maintenance & Calibration.^[1] Together they keep care safe and accurate.

Ophthalmic Pharmacology

A mydriatic such as phenylephrine dilates the pupil without affecting focusing; a cycloplegic (tropicamide, cyclopentolate, atropine) dilates and paralyzes accommodation for cycloplegic refraction. A miotic (pilocarpine) constricts the pupil. Dilating drops can precipitate angle-closure in narrow angles — counsel patients on red eye and pain.

Topical anesthetics (proparacaine, tetracaine) are used before tonometry and never dispensed for home use. Glaucoma drops include beta-blockers (timolol — caution in asthma/heart block), prostaglandins (latanoprost — lash/iris darkening), and carbonic anhydrase inhibitors. Teach punctal occlusion and a 5-minute wait between drops.^[4]

Microbiology & Sterilization

Standard precautions treat every patient’s fluids as infectious, and hand hygiene between patients is the single most important measure. The Spaulding classification sets the reprocessing level: critical items (enter sterile tissue) are sterilized, semicritical (touch mucosa — applanation tips) get high-level disinfection, and noncritical (intact skin — chin rests) get low-level disinfection.

An autoclave sterilizes with pressurized steam (commonly 121°C at 15 psi); chemical indicators confirm exposure and periodic biological (spore) tests confirm sterilization. COT-level microbiology also covers collecting specimens and cultures.^[5]

Instrument Maintenance

Equipment Maintenance & Calibration is 1% of the written exam but vital to accurate data. Routine care includes cleaning slit-lamp optics, replacing bulbs, disinfecting chin/forehead rests between patients, and checking calibration— for example, verifying the Goldmann tonometer against its calibration bar so a drifting instrument doesn’t give false IOPs. Calibrate biometry and topography units on schedule.^[1]

Surgical Assisting & Patient Services

The hands-on side of the Assisting category — Surgical Assisting and Ophthalmic Patient Services & Education (the single largest Assisting sub-topic at 8%).^[1]

Surgical Assisting & Lasers

A cataract (clouding of the natural lens) is removed by phacoemulsification — an ultrasonic probe emulsifies and aspirates the lens, then an IOL is implanted. The COT prepares and sterilizes instruments, positions and drapes the patient, maintains the sterile field, and documents — always within delegated tasks.

Sterile-field rules: only sterile touches sterile, keep the field in view and above waist level, and never reach over it. A pre-operative “time-out” verifies the correct patient, procedure, and eye (the Universal Protocol against wrong-site surgery).

LASIK reshapes the corneal stroma; a YAG capsulotomy clears a cloudy posterior capsule after cataract surgery. Laser safety (eyewear, door signage) is a COT responsibility.^[4]

Patient Services & Education

The technician reinforces the physician’s instructions — drops, follow-up, post-operative care — confirms understanding, and answers general questions within scope (never diagnosing). Teaching eye-drop self-administration is high-yield: wash hands, tilt back, pull down the lower lid to make a pocket, instill one drop without touching the eye, close gently, and use punctal occlusion.^[4]

Triage, Vital Signs & Emergencies

Patient Services also includes triage, vital signs, and CPR. A chemical eye burn is the classic triage emergency: begin immediate copious irrigation for at least 15–30 minutes before anything else. Sudden painless vision loss (possible artery occlusion, detachment, or stroke) and acute angle-closure (pain, halos, nausea, a fixed mid-dilated pupil) are urgent — notify the physician at once.^[1]

Office Responsibilities

The Office Responsibilities category is 14% of the written exam: medical ethics and legal/regulatory issues, communication, and administrative duties (the largest Office sub-topic at 8%).^[1]

Ethics, Legal & Regulatory

HIPAA protects patients’ protected health information — share it only on a need-to-know basis, keep records and screens secure, and never discuss patients publicly. Informed consentis the physician’s responsibility (explaining the procedure, risks, and alternatives); the technician may witness and document the signature but does not obtain the consent.

Negligence is failing to act as a reasonably prudent technician would; following protocols, documenting accurately, and staying within scope reduce liability. Quality assurance and accurate medical coding are also office responsibilities.^[1]

Communication & Scope

Clear, respectful communication — introducing yourself, explaining each test, and confirming understanding — improves cooperation and data quality. Critically, the technician’s scope of practice is to perform delegated testing and assist, notto diagnose, prescribe, or interpret results for the patient. When a patient asks “what’s my diagnosis?”, defer to the physician.^[2]

Administrative Duties & Coding

Administrative duties include scheduling and patient flow, scribing, managing forms and manuals, and supporting accurate coding and documentation for the record. The COT credential itself is renewed every 36 months with 27 continuing-education credits (at least 18 IJCAHPO Group A) or by re-testing.^[2]

How to Use This Study Guide

Work through the guide one module at a time. After each module, check it off in the contents to raise your exam-readiness score, then drill the same content in our free practice questions and flashcards — active recall and timed practice are what move knowledge into exam-day performance, for both the written exam and the Skill Evaluation.

• Weight your time by the category percentages. Assessments is 45% of the written exam and contains six of the seven Skill Evaluation stations — start there.
• Study the written and the skills together. Lensometry, fields, motility, keratometry, retinoscopy, refinement, and tonometry are tested on paper AND hands-on.
• Make refraction automatic. Retinoscopy motion rules, transposition, and the spherical equivalent recur all over the exam.
• Lock in the high-yield contrasts. Tropia vs. phoria, mydriatic vs. cycloplegic, optical vs. ultrasound biometry, and the Spaulding levels are repeatable points.
• Then prove it. When a module feels easy, confirm it with our practice questions and flashcards.

Common questions COT candidates search and get asked — each answered briefly and backed by an official source (IJCAHPO, NEI, NIH, or CDC). Tap any card to test yourself.

COT Glossary

Key COT terms in one place. Hover any dotted term throughout the guide for its definition; the full list is below.

COT

Certified Ophthalmic Technician — IJCAHPO's mid-level (intermediate) credential for an ophthalmic allied-health professional who performs clinical testing and assists the ophthalmologist.

IJCAHPO

International Joint Commission on Allied Health Personnel in Ophthalmology — the body that develops and awards the COA, COT, and COMT credentials.

COA

Certified Ophthalmic Assistant — IJCAHPO's entry-level credential, the rung below COT and a common prerequisite path to it.

COMT

Certified Ophthalmic Medical Technologist — IJCAHPO's advanced credential, the rung above COT.

cornea

The clear, dome-shaped front window of the eye; it provides about two-thirds of the eye's focusing power.

sclera

The tough white outer wall of the eye that protects and maintains its shape.

uvea

The middle vascular layer of the eye — the iris, ciliary body, and choroid.

retina

The inner neural layer that captures light and converts it to signals sent through the optic nerve.

macula

The central part of the retina responsible for sharp central vision; its center is the fovea.

fovea

The very center of the macula, densely packed with cones, giving the eye its sharpest detail vision.

optic disc

Where retinal ganglion axons exit the eye as the optic nerve; it has no photoreceptors, creating the physiologic blind spot.

ciliary body

The structure behind the iris that produces aqueous humor and controls accommodation.

aqueous humor

The clear fluid that fills the front of the eye, made by the ciliary body and drained through the trabecular meshwork.

trabecular meshwork

The drainage tissue in the anterior chamber angle; the main site of outflow resistance in open-angle glaucoma.

accommodation

The eye's ability to increase its focusing power for near objects by contracting the ciliary muscle and rounding the lens.

emmetropia

The state of having no refractive error — light focuses exactly on the retina.

myopia

Nearsightedness — light focuses in front of the retina; distance is blurry; corrected with a minus (concave) lens.

hyperopia

Farsightedness — light focuses behind the retina; near blurs first; corrected with a plus (convex) lens.

astigmatism

Unequal corneal or lens curvatures focus light at two points; corrected with a cylindrical lens.

presbyopia

The age-related loss of accommodation (after about 40), corrected with a reading add.

visual acuity

A measure of the clarity of vision, usually expressed as a Snellen fraction such as 20/20 or in logMAR units.

logMAR

Logarithm of the Minimum Angle of Resolution — a uniform-step acuity scale (each line is 0.1 log unit) used on ETDRS charts.

pinhole

An occluder with small holes; if acuity improves through it, the cause is uncorrected refractive error rather than pathology.

lensometry

Measuring the power (sphere, cylinder, axis, add, prism) of an existing spectacle lens by neutralizing it; also called focimetry.

retinoscopy

An objective refraction in which a streak of light is swept across the pupil and the reflex is neutralized with lenses.

refinement

The subjective step that fine-tunes the refraction using the phoropter and the Jackson Cross Cylinder.

spherical equivalent

The single sphere that best represents a sphero-cylindrical lens: sphere plus half the cylinder.

transposition

Rewriting a prescription between plus-cylinder and minus-cylinder forms (combine sphere and cylinder, flip the cylinder sign, rotate the axis 90 degrees).

prism diopter

A unit of prism deviation (symbol Δ): 1Δ displaces an image 1 cm at 1 meter.

vertex distance

The distance from the back of a spectacle lens to the cornea (about 12–14 mm); it must be accounted for in high-power lenses.

keratometry

Measuring the curvature of the central cornea along its two principal meridians (the K readings) and corneal astigmatism.

topography

A color map of the entire corneal surface curvature, used to detect irregular astigmatism, keratoconus, and to plan refractive surgery.

biometry

Measuring ocular dimensions (chiefly axial length and keratometry) to calculate the intraocular lens power for cataract surgery.

axial length

The front-to-back length of the eye; the most influential measurement in IOL power calculation.

pachymetry

Measurement of corneal thickness, important for interpreting IOP and screening for refractive surgery.

tonometry

Measuring intraocular pressure (IOP); Goldmann applanation tonometry is the gold standard.

IOP

Intraocular pressure — the fluid pressure inside the eye; normally about 10–21 mmHg.

applanation tonometry

Measuring IOP by flattening a fixed area of the cornea (Goldmann); the force needed equals the pressure (Imbert-Fick principle).

RAPD

Relative afferent pupillary defect (Marcus Gunn pupil) — found on the swinging-flashlight test; signals optic nerve or severe retinal disease.

anisocoria

Unequal pupil sizes; note whether the difference is greater in light or dark to localize the cause.

tropia

A manifest (constant) eye misalignment present with both eyes open, revealed by the cover-uncover test.

phoria

A latent eye deviation controlled by fusion, revealed only when the eyes are dissociated (alternate cover test).

esotropia

An inward-turning eye misalignment.

exotropia

An outward-turning eye misalignment.

cover test

A test for ocular misalignment in which one eye is covered and the other is watched for a fixation shift.

scotoma

An area of reduced or absent vision within the visual field, such as the blind spot or a glaucomatous defect.

perimetry

Visual field testing that maps a patient's field of vision (static automated or kinetic Goldmann).

OCT

Optical coherence tomography — a non-invasive light-based scan giving cross-sections of the retina and optic nerve.

fluorescein angiography

Imaging retinal blood flow after injecting fluorescein dye; its rare serious risk is anaphylaxis.

A-scan

An ultrasound that measures axial length for IOL power; applanation touches the cornea, immersion uses a standoff.

B-scan

A two-dimensional ultrasound of the posterior eye used when the view is blocked (dense cataract, vitreous hemorrhage).

mydriatic

A drug that dilates the pupil; phenylephrine dilates without paralyzing accommodation.

cycloplegic

An anticholinergic drug (tropicamide, cyclopentolate, atropine) that both dilates and paralyzes accommodation.

miotic

A drug that constricts the pupil (such as pilocarpine), historically used in glaucoma and angle-closure.

punctal occlusion

Pressing the inner corner of the eye after instilling drops to improve absorption and reduce systemic effects.

standard precautions

Treating every patient's blood and body fluids as potentially infectious through hand hygiene, PPE, and disinfection.

autoclave

A device that sterilizes instruments with pressurized steam (commonly 121°C at 15 psi), killing all microorganisms and spores.

Spaulding classification

A scheme that grades instruments as critical (sterilize), semicritical (high-level disinfect), or noncritical (low-level).

phacoemulsification

Standard cataract surgery in which an ultrasonic probe emulsifies and aspirates the cloudy lens before an IOL is implanted.

IOL

Intraocular lens — the artificial lens implanted during cataract surgery.

YAG capsulotomy

A laser procedure that opens a cloudy posterior capsule (secondary cataract) after cataract surgery.

glaucoma

A progressive optic neuropathy (cupping and visual field loss), often linked to elevated IOP, causing irreversible vision loss if untreated.

cataract

A clouding of the eye's natural crystalline lens that blurs vision and causes glare.

HIPAA

The Health Insurance Portability and Accountability Act — federal law protecting patients' protected health information.

scope of practice

The clinical tasks a technician is trained and authorized to perform under physician supervision — testing and assisting, not diagnosing.

COT Study Guide FAQ

References

1. 1.International Joint Commission on Allied Health Personnel in Ophthalmology (IJCAHPO). “Criteria for Certification & Recertification — COT Examination Content Outline (effective 8/1/2018).” IJCAHPO. ↑
2. 2.IJCAHPO. “Certified Ophthalmic Technician (COT) — Eligibility & Recertification Requirements.” jcahpo.org. ↑
3. 3.National Eye Institute (NEI). “Learn About Eye Health — Anatomy, Refractive Errors & Eye Conditions.” NIH/NEI. ↑
4. 4.National Institutes of Health / National Library of Medicine. “StatPearls & MedlinePlus (visual acuity, tonometry, retinoscopy, biometry, OCT, mydriatics).” NIH/NLM. ↑
5. 5.Centers for Disease Control and Prevention (CDC). “Guideline for Disinfection and Sterilization (Spaulding Classification) & Standard Precautions.” CDC. ↑
6. 101.International Joint Commission on Allied Health Personnel in Ophthalmology (IJCAHPO). “Certified Ophthalmic Technician — Role and Criteria.” jcahpo.org, accessed 19 June 2026. ↑

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