Free CPO™ Practice Test: Sample Questions with Answers

1. Question 1

   In the Snellen fraction 20/40, what does the denominator (40) represent?

   1. A. Number of letters correctly read on that line
   2. B. Distance in feet the patient stood from the chart
   3. C. Distance a normal eye could still read that line
   4. D. Smallest letter size printed on the chart
   Show answer to question 1

   Answer: C. Distance a normal eye could still read that line

   The numerator is the test distance (usually 20 feet); the denominator is the distance at which a person with unimpaired acuity could still resolve that letter size. A larger denominator means worse acuity.

2. Question 2

   During acuity testing, a patient's vision improves when looking through a pinhole occluder. What does this most likely indicate?

   1. A. An uncorrected or undercorrected refractive error
   2. B. Early cataract formation developing along the visual axis
   3. C. Macular degeneration affecting central vision
   4. D. Optic nerve damage from advanced glaucoma
   Show answer to question 2

   Answer: A. An uncorrected or undercorrected refractive error

   Pinhole testing isolates central rays to reduce optical blur; if acuity improves, the deficit is likely refractive (correctable with lenses) rather than caused by media opacity or retinal or nerve pathology.

3. Question 3

   What is the 'consensual' pupillary light response?

   1. A. Dilation of the lit eye in dim light
   2. B. Constriction of the other, unlit eye
   3. C. No pupillary response in either eye
   4. D. Constriction seen only in the lit eye
   Show answer to question 3

   Answer: B. Constriction of the other, unlit eye

   Because the pupillary light reflex pathway signals both irises at once, shining light into one eye also causes the other, unlit eye to constrict, which is the consensual response.

4. Question 4

   A statistically normal adult intraocular pressure, measured by applanation tonometry, generally falls in which range?

   1. A. About 1 to 9 mmHg
   2. B. About 10 to 21 mmHg
   3. C. About 22 to 30 mmHg
   4. D. About 31 to 40 mmHg
   Show answer to question 4

   Answer: B. About 10 to 21 mmHg

   Population studies place statistically normal intraocular pressure at roughly 10 to 21 mmHg, with an average near 15-16 mmHg; readings above this range warrant closer evaluation for glaucoma risk.

5. Question 5

   The Ishihara plates are designed primarily to screen for:

   1. A. Red-green color vision deficiency
   2. B. A loss of peripheral visual field
   3. C. A reduced sense of depth perception
   4. D. Blue-yellow color vision deficiency
   Show answer to question 5

   Answer: A. Red-green color vision deficiency

   Ishihara pseudoisochromatic plates are designed specifically to detect red-green color deficiencies, the most common inherited color vision defect, and are not reliable for blue-yellow defects.

6. Question 6

   During the cover-uncover test, if the uncovered fellow eye shifts to take up fixation as soon as the other eye is covered, this indicates:

   1. A. A manifest deviation (tropia) in that eye
   2. B. A significant refractive error only in the covered eye
   3. C. Normal, well-aligned binocular vision
   4. D. Reduced accommodation in that eye
   Show answer to question 6

   Answer: A. A manifest deviation (tropia) in that eye

   If the fellow eye must move to pick up fixation the instant the other eye is covered, it was misaligned even before any dissociation was introduced -- the hallmark of a manifest tropia, as opposed to a phoria that only appears under cover.

7. Question 7

   The Amsler grid, a pattern of straight horizontal and vertical lines around a central fixation dot, is used chairside mainly to detect:

   1. A. Central field distortion or missing areas from macular disease
   2. B. Reduced color discrimination on the red-green axis
   3. C. A peripheral visual field cut caused by advanced optic nerve damage
   4. D. An uncorrected astigmatic refractive error
   Show answer to question 7

   Answer: A. Central field distortion or missing areas from macular disease

   While fixating the central dot, a patient with macular disease may report wavy, distorted, or missing lines (metamorphopsia or a scotoma) nearby, so the Amsler grid is a quick screen for central field disturbance rather than peripheral loss, color vision, or refractive error.

8. Question 8

   What is the correct technique for instilling a diagnostic drop into the lower conjunctival fornix?

   1. A. Place the drop directly on the open cornea
   2. B. Pull the upper lid up; have the patient look down
   3. C. Close both eyes and place the drop on the lid
   4. D. Pull the lower lid down; have the patient look up
   Show answer to question 8

   Answer: D. Pull the lower lid down; have the patient look up

   Pulling the lower lid down while the patient looks up exposes the lower fornix, a comfortable pocket for the drop that avoids the sensitive cornea and reduces reflex blinking away of the medication.

9. Question 9

   Phenylephrine drops warrant extra caution in patients with:

   1. A. Mild seasonal allergy symptoms
   2. B. Uncontrolled blood pressure
   3. C. A history of contact-lens use
   4. D. A prior LASIK eye procedure
   Show answer to question 9

   Answer: B. Uncontrolled blood pressure

   Phenylephrine is a systemic alpha-adrenergic stimulant that can raise blood pressure and heart rate, so it is used cautiously in patients with uncontrolled hypertension or cardiac conditions.

10. Question 10

    To correct an error already written in a patient's chart, a technician should:

    1. A. Cover the mistake with correction fluid
    2. B. Erase it fully and rewrite the entry
    3. C. Draw one line through it and initial it
    4. D. Remove the page and start it over
    Show answer to question 10

    Answer: C. Draw one line through it and initial it

    A single strikethrough with initials and a date keeps the original entry legible, preserving the record's integrity; obliterating or erasing an entry can look like an attempt to conceal it.

11. Question 11

    When should soap and water be used for hand hygiene instead of an alcohol-based rub?

    1. A. Whenever the assistant is in a hurry
    2. B. Never; alcohol rub is always preferred
    3. C. Only at the start of the workday
    4. D. Whenever hands are visibly soiled
    Show answer to question 11

    Answer: D. Whenever hands are visibly soiled

    Alcohol-based hand rubs do not adequately remove visible dirt, blood, or other organic material, so soap and water washing is required whenever hands are visibly soiled.

12. Question 12

    On a chart note, visual acuity recorded as "20/25 cc" means the test was performed:

    1. A. Without any correction in place
    2. B. Under cycloplegic dilation
    3. C. Using the pinhole occluder
    4. D. With glasses or contacts on
    Show answer to question 12

    Answer: D. With glasses or contacts on

    "cc" (cum correctione) means the acuity was measured with the patient's habitual correction; "sc" (sine correctione) denotes testing without correction.

13. Question 13

    A patient says a medication 'always upsets my stomach.' How should this be documented?

    1. A. As a severe allergy needing an urgent alert
    2. B. It should not be written in the chart
    3. C. As a side effect, not a true drug allergy
    4. D. As a reason to stop every current medication
    Show answer to question 13

    Answer: C. As a side effect, not a true drug allergy

    Gastrointestinal upset is a common side effect rather than an immune-mediated allergic reaction, so charting it accurately avoids wrongly labeling the patient as allergic to a medication they may still need.

14. Question 14

    In confrontation visual field testing, the examiner should cover:

    1. A. The same eye as the patient
    2. B. Neither eye, keeping both open
    3. C. Both eyes at the same time
    4. D. The eye opposite the patient's
    Show answer to question 14

    Answer: D. The eye opposite the patient's

    Covering the eye opposite the patient's covered eye aligns the two open eyes across from each other, letting the examiner compare the patient's peripheral responses against their own normal field as a reference.

15. Question 15

    A high false-positive rate on a visual field test suggests that the patient:

    1. A. Was wearing the wrong trial lens
    2. B. Fell asleep during part of the test
    3. C. Has a genuine peripheral field defect
    4. D. Answered when no stimulus was shown
    Show answer to question 15

    Answer: D. Answered when no stimulus was shown

    False positives occur when the machine presents no stimulus and the patient still responds, suggesting an overeager response pattern that reduces confidence in the test's reliability.

16. Question 16

    Before measuring a patient's spectacles, a lensometer should first be checked by confirming it reads:

    1. A. The prior patient's power exactly
    2. B. Plano with nothing in the lens stop
    3. C. Minus one diopter as a factory default
    4. D. A fixed offset of plus two diopters
    Show answer to question 16

    Answer: B. Plano with nothing in the lens stop

    With no lens in the stop, the instrument should read zero (plano); if it doesn't, it needs recalibration before any patient's lenses are measured.

17. Question 17

    Titmus and Randot stereoacuity tests require the patient to wear:

    1. A. Polarized viewing glasses
    2. B. An occlusive eye patch
    3. C. No special eyewear at all
    4. D. Red-green anaglyph glasses
    Show answer to question 17

    Answer: A. Polarized viewing glasses

    Titmus and Randot tests use vectographic plates viewed through polarized glasses, which separate the image seen by each eye; red-green glasses are used for other binocular vision tests.

18. Question 18

    Compared to a patient's distance PD, near PD is generally:

    1. A. Slightly smaller, from convergence at near
    2. B. Identical, because PD does not change with gaze
    3. C. Impossible to estimate without a phoropter
    4. D. Slightly larger, since near pupils widen
    Show answer to question 18

    Answer: A. Slightly smaller, from convergence at near

    The eyes converge when fixating a near target, moving the visual axes closer together, so near PD measures a few millimeters less than distance PD.

19. Question 19

    Esotropia is best described as an eye that is deviated:

    1. A. Upward, toward the brow
    2. B. Inward, toward the nose
    3. C. Outward, toward the ear
    4. D. Downward, toward the cheek
    Show answer to question 19

    Answer: B. Inward, toward the nose

    The prefix eso- means inward; an esotropic eye is turned in toward the nose. Exo- (outward), hyper- (upward), and hypo- (downward) describe the other deviation directions.

Clinical Principles, Testing, and Procedures study guide →

1. Question 20

   A soft contact lens wearer calls reporting a painful, red eye with light sensitivity that began overnight. What should staff advise?

   1. A. Continue lens wear and use artificial tears
   2. B. Stop lens wear now and see the doctor promptly
   3. C. Switch to daily disposables and follow up in a week
   4. D. Rinse the lens in saline and reinsert it before bed
   Show answer to question 20

   Answer: B. Stop lens wear now and see the doctor promptly

   Pain, redness, and photophobia together in a lens wearer are hallmark warning signs of microbial keratitis, a sight-threatening emergency that requires the lens to come off and prompt evaluation rather than reassurance or reinsertion.

2. Question 21

   Why do eye care providers warn contact lens wearers against rinsing lenses or cases with tap water?

   1. A. Tap water can carry organisms linked to keratitis
   2. B. Tap water is generally too acidic for lens materials
   3. C. Tap water evaporates too fast for a full rinse
   4. D. Tap water leaves a residue that is only cosmetic
   Show answer to question 21

   Answer: A. Tap water can carry organisms linked to keratitis

   Tap water, and even some bottled or well water, can harbor Acanthamoeba and other organisms; exposing lenses or cases to it has been linked to a sight-threatening corneal infection called Acanthamoeba keratitis.

3. Question 22

   A patient removes a lens from a hydrogen peroxide case before the neutralization cycle finishes and inserts it. What should staff expect the patient to report?

   1. A. No symptoms at all, since peroxide is inert on contact
   2. B. A gradual haze appearing over the next several days
   3. C. Mild blur that clears after a minute
   4. D. Severe burning, stinging, and tearing right away
   Show answer to question 22

   Answer: D. Severe burning, stinging, and tearing right away

   Unneutralized hydrogen peroxide is a strong oxidizer, so skipping the neutralizing step causes immediate, significant pain and irritation, not a delayed or mild effect.

4. Question 23

   A long-time hydrogel wearer switches to silicone hydrogel lenses. Which complication is this switch mainly meant to reduce?

   1. A. Allergic reactions to cleaning solution
   2. B. Contamination inside the lens case
   3. C. Corneal hypoxia and neovascularization
   4. D. Deposits left behind by eye cosmetics
   Show answer to question 23

   Answer: C. Corneal hypoxia and neovascularization

   The main clinical advantage of silicone hydrogels is far higher oxygen delivery to the cornea, which reduces hypoxia-driven changes such as neovascularization that were common with older, lower-oxygen hydrogel lenses.

5. Question 24

   Toric soft lenses often include design features like prism ballast or thin zones. Their main purpose is to:

   1. A. Increase the water content of the lens material
   2. B. Make the lens easier to remove with a fingertip
   3. C. Keep the lens from rotating out of alignment
   4. D. Reduce the total oxygen the cornea receives
   Show answer to question 24

   Answer: C. Keep the lens from rotating out of alignment

   Because astigmatism correction depends on a specific axis, toric lenses use weighting or thinning features to resist rotation, so the correcting cylinder stays aligned during blinking.

Contact Lenses study guide →

1. Question 25

   A patient gets headaches and sees double print with new glasses. Which fitting error is most likely?

   1. A. An inaccurate pupillary distance measurement
   2. B. A lens coating applied unevenly on one side
   3. C. A frame temple cut slightly too long overall
   4. D. Nose pads that were set slightly too wide
   Show answer to question 25

   Answer: A. An inaccurate pupillary distance measurement

   An inaccurate PD decenters the optical centers from the patient's visual axes, inducing unwanted prism that commonly causes eyestrain, headache, or double vision.

2. Question 26

   By standard convention, the axis value of a cylinder correction on a spectacle Rx is written within which range?

   1. A. -90 to +90 degrees
   2. B. 0 to 90 degrees
   3. C. 0 to 360 degrees
   4. D. 1 to 180 degrees
   Show answer to question 26

   Answer: D. 1 to 180 degrees

   An axis describes a line, not a direction, so values repeat every 180 degrees; by convention it is always recorded as a whole number from 1 to 180.

3. Question 27

   Which lens material is most often specified for occupational safety eyewear because of its high impact resistance?

   1. A. Standard CR-39 lens material
   2. B. Polycarbonate lens material
   3. C. Basic crown glass material
   4. D. High-index 1.67 lens material
   Show answer to question 27

   Answer: B. Polycarbonate lens material

   Polycarbonate is roughly ten times more impact-resistant than regular plastic lens material, making it the standard choice for occupational and safety eyewear.

4. Question 28

   Which lens shape corrects myopia (nearsightedness)?

   1. A. A plano lens with no curve on either side
   2. B. A prism lens that shifts the image sideways
   3. C. A convex lens that converges incoming rays
   4. D. A concave lens that diverges incoming rays
   Show answer to question 28

   Answer: D. A concave lens that diverges incoming rays

   Myopic eyes focus light in front of the retina, so a minus (concave) lens diverges rays before they enter the eye, moving the focal point back onto the retina.

Ophthalmic Optics and Dispensing study guide →

1. Question 29

   A patient's adult son calls asking for a copy of his mother's exam results. What should staff do first?

   1. A. Fax the full chart to any number he provides
   2. B. Read the results to him since he is family
   3. C. Confirm the patient authorized that disclosure
   4. D. Have him email a release that he signs himself
   Show answer to question 29

   Answer: C. Confirm the patient authorized that disclosure

   Without the patient's own authorization, or the patient present and agreeing, staff cannot disclose records to a relative. A family relationship, or a release signed by the requester instead of the patient, does not satisfy that requirement.

2. Question 30

   What is a 'copay' in insurance terms?

   1. A. The full price charged before insurance is applied
   2. B. The yearly amount owed before coverage begins
   3. C. A fixed fee paid at the time of a covered visit
   4. D. A percentage of the bill owed after the deductible
   Show answer to question 30

   Answer: C. A fixed fee paid at the time of a covered visit

   A copay is a flat, fixed amount collected at the time of service. This is different from a deductible, an annual threshold, or coinsurance, a percentage split, which the other choices describe.

3. Question 31

   A patient asks the technician to explain what her visual field test results mean for her glaucoma. What should the technician do?

   1. A. Give a full interpretation since the test was just performed
   2. B. Compare the results to the patient's last visit personally
   3. C. Explain that the doctor will review the results with her
   4. D. Tell the patient the results look normal to avoid worry
   Show answer to question 31

   Answer: C. Explain that the doctor will review the results with her

   Interpreting test results and diagnosing are outside a technician's scope of practice; results and their clinical meaning should come from the doctor, even when staff performed the testing.

4. Question 32

   What does an Explanation of Benefits (EOB) sent to a patient show?

   1. A. How a claim was processed and what the patient owes
   2. B. A pre-approval needed before scheduling surgery
   3. C. The patient's full diagnosis and treatment plan
   4. D. A list of providers currently in the plan's network
   Show answer to question 32

   Answer: A. How a claim was processed and what the patient owes

   An EOB is a statement from the insurer explaining how a submitted claim was adjudicated, including what was covered and what balance remains. It is not a bill, a referral, or a provider directory.

Professional Issues study guide →

1. Question 33

   Which structure supplies the largest share of the eye's total focusing power?

   1. A. The crystalline lens behind the iris
   2. B. The cornea at the front of the eye
   3. C. The vitreous gel behind the lens
   4. D. The aqueous fluid behind the cornea
   Show answer to question 33

   Answer: B. The cornea at the front of the eye

   The cornea, where light passes from air into the eye, provides about two-thirds of the eye's focusing power. The crystalline lens supplies most of the rest and is the part that can change its power for near focus, which is why many people assume it does most of the work.

2. Question 34

   The uvea, also called the uveal tract, is made up of which three structures?

   1. A. The sclera, choroid, and retina
   2. B. The cornea, iris, and crystalline lens
   3. C. The iris, ciliary body, and choroid
   4. D. The ciliary body, zonules, and lens
   Show answer to question 34

   Answer: C. The iris, ciliary body, and choroid

   The uvea is the eye's pigmented, blood-rich middle layer: the iris in front, the ciliary body behind it, and the choroid between the retina and sclera, which is why inflammation of any of them is called uveitis. The sclera and retina are the outer and inner layers around it, and the cornea, zonules and lens are not part of it.

3. Question 35

   A patient asks why the optometrist screens for open-angle glaucoma at routine visits when his eyes feel and see fine. Which explanation is accurate?

   1. A. It first blurs the central vision used for reading
   2. B. Early loss of side vision usually goes unnoticed
   3. C. Rising eye pressure is usually felt as an ache
   4. D. A normal reading on the eye chart rules it out
   Show answer to question 35

   Answer: B. Early loss of side vision usually goes unnoticed

   Open-angle glaucoma is typically painless and damages peripheral (side) vision first, so patients rarely notice it until permanent loss is well advanced, which is why it is screened for at routine exams. Raised pressure is not usually felt, and 20/20 acuity does not rule it out because central vision is spared until late.

4. Question 36

   A patient reads 'blepharitis OU' on her visit summary and asks what it means. Which plain-language explanation is correct?

   1. A. Inflamed corneas, the clear front windows of both eyes
   2. B. Inflamed membranes over the whites of both eyes
   3. C. Inflamed tear-draining sacs near the nose on both sides
   4. D. Inflamed eyelid margins along the lashes of both eyes
   Show answer to question 36

   Answer: D. Inflamed eyelid margins along the lashes of both eyes

   Blephar- means eyelid and -itis means inflammation, so blepharitis is inflammation of the eyelids, usually the lid margins where the lashes grow, and OU means both eyes. Inflammation of the cornea is keratitis, of the conjunctiva is conjunctivitis, and of the tear sac is dacryocystitis.

Science of the Eye study guide →