21 Visual Acuity, Pupils & Motility Practice Questions & Answers

1. 1. A distance acuity is recorded as 20/60. What does the denominator 60 represent?

   • A.The distance in feet at which the patient was seated from the chart
   • B.The height of the smallest letter the patient read, in millimeters
   • C.The distance at which an eye with normal acuity reads that line✓ Answer
   • D.The number of letters the patient identified on that line

   The Snellen fraction compares the actual test distance (numerator) with the distance at which an eye of normal acuity resolves that same line (denominator). So 20/60 means the patient at 20 feet sees what a normal eye sees at 60 feet, and a larger denominator therefore means poorer acuity.

   Source: Snellen acuity notation, standard ophthalmic clinical practice; IJCAHPO Core Criteria Handbook, Visual Assessment content areaReport a problem with this question

2. 2. An adult patient does not know the alphabet used on the chart and speaks a language the staff does not share. What is the most appropriate way to measure distance acuity?

   • A.Test near acuity from the reading card and omit distance acuity
   • B.Use a tumbling E chart and have the patient point the direction of each E✓ Answer
   • C.Use the standard letter chart and score whatever letters are named
   • D.Record the distance acuity as unobtainable because of the barrier

   A directional (tumbling E) chart removes the need to read or name letters, because the patient only indicates which way the arms of the E point; the same applies to matching cards and picture optotypes. The assistant adapts the optotype to the patient in front of them rather than abandoning or degrading the measurement.

   Source: IJCAHPO Core Criteria Handbook, Visual Assessment task list (testing preliterate, illiterate, non-verbal or non-English-speaking patients)Report a problem with this question

3. 3. At the standard testing distance the patient cannot identify the largest optotype on the chart. What should the assistant do next?

   • A.Walk the patient closer and record the distance used as the numerator✓ Answer
   • B.Record the acuity as hand motion and continue with the other eye
   • C.Add the pinhole occluder and repeat the largest line at the same distance
   • D.Record count fingers at the distance the patient sits from the chart

   Chart optotypes still give a more precise measurement than count fingers, so the patient is brought forward until the largest optotype is seen and the actual distance becomes the numerator, as in 10/200 or 5/200. Dropping straight to count fingers discards resolvable detail and overstates the vision loss.

   Source: IJCAHPO Core Criteria Handbook, Visual Assessment task list (recording acuity at all levels); AAO Ophthalmic Medical Assisting, visual acuity measurementReport a problem with this question

4. 4. A patient cannot identify any optotype but can count the examiner's fingers. What makes the recorded entry complete?

   • A.Count fingers, with the room illumination used during testing
   • B.Count fingers, with the number of fingers the patient identified
   • C.Count fingers, with the pinhole acuity obtained afterward
   • D.Count fingers, with the distance at which they were counted✓ Answer

   Count fingers and hand motion are distance-dependent findings: fingers counted close to the face and fingers counted across the room describe very different vision, so an entry without the distance cannot be compared with the last visit. The same logic drives the descending sequence count fingers, hand motion, light perception, no light perception, with light perception further qualified as with or without projection.

   Source: IJCAHPO Core Criteria Handbook, Visual Assessment task list (recording count fingers, hand motion, light perception, no light perception)Report a problem with this question

5. 5. Acuity of 20/80 improves to 20/25 through the pinhole. What does this indicate?

   • A.An optic nerve disorder is limiting the acuity obtained
   • B.A lens or corneal opacity is scattering light and limiting acuity
   • C.Uncorrected refractive error accounts for the reduced acuity✓ Answer
   • D.Macular disease is reducing the central retinal acuity

   The pinhole admits only a narrow central bundle of rays, shrinking the blur circle on the retina and so neutralising most defocus. Acuity that improves behind it is therefore optically limited, whereas failure to improve points toward media opacity, macular or optic nerve causes; the pinhole result is recorded separately and never replaces the entry made without it.

   Source: AAO Ophthalmic Medical Assisting, pinhole testing; IJCAHPO Core Criteria Handbook, Visual Assessment task listReport a problem with this question

6. 6. When each eye is tested separately, how should the occluder be positioned?

   • A.Held over the tested eye while the other eye reads
   • B.Rested on the spectacle lens of the eye being tested
   • C.Pressed firmly against the eye so the patient cannot peek
   • D.Near the eye, without pressing on the globe or lids✓ Answer

   Pressure on the globe transiently distorts the cornea, so the pressed eye reads worse when its turn comes and the recorded acuity is falsely low. The occluder must block the fellow eye completely, including any gap at the nose or above the frame, while staying off the eye itself; the usual order is right eye, left eye, then both together.

   Source: AAO Ophthalmic Medical Assisting, occlusion technique for monocular acuity testingReport a problem with this question

7. 7. Stereoacuity results are recorded in seconds of arc. How is the result interpreted?

   • A.A larger number of seconds of arc means finer stereopsis
   • B.A smaller number of seconds of arc means finer stereopsis✓ Answer
   • C.The number gives the near test distance used in centimeters
   • D.The number gives the prism diopters of the deviation found

   Seconds of arc express the smallest retinal disparity the patient can still appreciate as depth, so the finer the stereopsis, the smaller the number that can be detected. The test is valid only when the polarised glasses are worn over the habitual near correction and the booklet is held at the distance the plates are calibrated for.

   Source: IJCAHPO Core Criteria Handbook, Visual Assessment task list (testing and recording stereoacuity)Report a problem with this question

8. 8. During near point of convergence testing an accommodative target is moved slowly toward the nose. What two findings are recorded?

   • A.The break, and the recovery when fusion returns, each in centimeters✓ Answer
   • B.The stereoacuity, and the deviation seen at distance
   • C.The break, and the pupil size at the moment of the break
   • D.The near acuity, and the accommodative amplitude in diopters

   The break is the point at which fusion fails, seen as one eye drifting out or reported as doubling, and the recovery is the point at which fusion is regained as the target is withdrawn; both are measured from the patient in centimeters. A break that is far out from the nose, especially with a still more remote recovery, describes a receded near point of convergence and is reported to the ophthalmologist.

   Source: IJCAHPO Core Criteria Handbook, Visual Assessment task list (near point of accommodation and convergence)Report a problem with this question

9. 9. A patient has a 2+ relative afferent pupillary defect of the right eye. What would you expect the pupil sizes to be in room light?

   • A.Unequal in dim light only, with the right pupil dilating more
   • B.The left pupil larger, because of the consensual response
   • C.Equal, because the defect is afferent and the efferent pathway is intact✓ Answer
   • D.The right pupil larger, because it constricts less to light

   A relative afferent pupillary defect is a conduction problem on the sensory side of the reflex arc; the motor supply to both irides is unaffected, and because each pupil receives the summed drive from both eyes, the two pupils rest at the same size. The defect is revealed only by comparing the two eyes during the swinging flashlight test, so anisocoria at rest points to a different problem entirely.

   Source: AAO Ophthalmic Medical Assisting, pupillary examination; IJCAHPO Core Criteria Handbook, Pupil Assessment content areaReport a problem with this question

10. 10. During the swinging flashlight test, why is the patient asked to fixate a distant target in a dim room?

    • A.To equalize the amount of light reaching each retina
    • B.To make the consensual reaction easier to observe
    • C.To keep the patient from moving the head during the test
    • D.To avoid near miosis and let the pupils dilate✓ Answer

    Looking at a near object triggers the near reflex, and the resulting accommodative miosis holds both pupils small so that any difference in the light response is masked. A dim room plus distance fixation lets the pupils sit large, giving the light more room to show a difference as it is swung briskly from one eye to the other.

    Source: AAO Ophthalmic Medical Assisting, swinging flashlight test techniqueReport a problem with this question

11. 11. Which finding would NOT by itself produce a relative afferent pupillary defect?

    • A.A central retinal artery occlusion
    • B.A dense cataract in the right eye✓ Answer
    • C.An optic neuritis in the right eye
    • D.A macula-involving detachment

    A cataract scatters light but still delivers it to the retina, so the total light signal reaching the midbrain is essentially preserved and the pupils respond symmetrically; a dense lens opacity can even slightly favour the affected eye. Optic nerve and widespread retinal disease reduce the signal itself, which is what an afferent defect measures, so a relative afferent pupillary defect is never explained away by cataract, corneal scar, refractive error, or an efferent problem such as pharmacologic dilation.

    Source: AAO Ophthalmic Medical Assisting, interpretation of the relative afferent pupillary defectReport a problem with this question

12. 12. Pupils measure 4 mm and 3 mm in room light and 6 mm and 3.5 mm in dim light. Which pupil is abnormal, and why?

    • A.The smaller pupil, because it constricts more than the fellow eye
    • B.The larger pupil, because the difference is greater in the dark
    • C.The smaller pupil, because the difference is greater in the dark✓ Answer
    • D.The larger pupil, because it fails to constrict in bright light

    The abnormal pupil is the one that fails to do its job in the lighting condition where the difference widens. Here the gap grows from 1 mm in light to 2.5 mm in the dark, so the small pupil is the one that will not dilate; had the difference been the same in light and dark with brisk reactions, a physiologic anisocoria would be the likely explanation.

    Source: IJCAHPO Core Criteria Handbook, Pupil Assessment task list (measure and compare pupils in light and dim illumination)Report a problem with this question

13. 13. A patient's anisocoria is greater in bright light than in dim light. What does this pattern indicate?

    • A.Both pupils are normal, a physiologic anisocoria
    • B.The room lighting was too bright during measurement
    • C.The larger pupil is abnormal and constricts poorly✓ Answer
    • D.The smaller pupil is abnormal and dilates poorly

    Bright light is the condition that demands constriction, so a difference that widens in light identifies the pupil that constricts poorly, which is the larger one. This is the mirror image of anisocoria greater in the dark, where the smaller pupil is the one failing to dilate; the assistant records both measurements and reports the pattern rather than naming a cause.

    Source: IJCAHPO Core Criteria Handbook, Pupil Assessment task list (compare pupil size and reactivity in light and dark)Report a problem with this question

14. 14. A patient is scheduled for dilation. When should pupil size, shape and reactivity be assessed?

    • A.Before any drop is instilled, while responses are valid✓ Answer
    • B.Only when the patient reports a change in vision
    • C.After dilation, when the pupil margin is easiest to see
    • D.At any time, since dilating drops do not alter the findings

    Dilating drops paralyse the iris sphincter or stimulate the dilator, abolishing the light reaction and the size comparison for hours, so any pupil finding obtained afterward is pharmacologic and not the patient's own. The same rule of testing before you alter the eye applies to motility and to anything else disturbed by drops or by pressure on the globe, and the chart should note prior drops, trauma or intraocular surgery before the findings are interpreted.

    Source: IJCAHPO Core Criteria Handbook, Pupil Assessment content area; AAO Ophthalmic Medical Assisting, sequence of the ophthalmic workupReport a problem with this question

15. 15. Which pupil entry in the chart is complete enough for the ophthalmologist?

    • A.Round and reactive, with the dilating drop time noted
    • B.Pupil sizes in room light only, with the reaction noted
    • C.PERRLA, recorded for both eyes at the end of the workup
    • D.Sizes in light and dark for each eye, shape, reaction, RAPD status✓ Answer

    The physician has to be able to reconstruct the examination from the chart, and the light-versus-dark comparison is precisely what decides which pupil is abnormal, so a single measurement or an abbreviation such as PERRLA leaves the key comparison missing. Shape matters because an irregular or peaked pupil suggests previous trauma or surgery, and the presence or absence of a relative afferent defect must be stated explicitly rather than assumed.

    Source: IJCAHPO Core Criteria Handbook, Pupil Assessment and documentation of clinical findingsReport a problem with this question

16. 16. Light is shone into the right eye and the assistant watches the left pupil constrict. What has been observed?

    • A.The direct reaction of the left pupil
    • B.The consensual reaction of the left pupil✓ Answer
    • C.An afferent defect of the right optic nerve
    • D.The near reaction of the left pupil

    The direct reaction is the response of the illuminated eye itself, while the consensual reaction is the response of the fellow eye, which occurs because the afferent signal crosses to supply both third nerve pathways. Testing both therefore separates the sensory side from the motor side: a pupil that reacts consensually but not directly implicates its own efferent supply rather than the light signal.

    Source: AAO Ophthalmic Medical Assisting, direct and consensual pupillary responsesReport a problem with this question

17. 17. To evaluate the depressing action of the superior oblique, how is the eye positioned?

    • A.In abduction, then asked to look down
    • B.In abduction, then asked to look up
    • C.In primary position, straight ahead
    • D.In adduction, then asked to look down✓ Answer

    The pull of the obliques lines up with the visual axis when the eye is adducted, so the superior oblique acts almost purely as a depressor in that position and the inferior oblique as an elevator. The vertical recti are the reverse: they line up with the visual axis in abduction, which is why the superior rectus is tested as the elevator and the inferior rectus as the depressor with the eye turned out.

    Source: IJCAHPO Core Criteria Handbook, Ocular Motility Testing task list (extraocular muscle functions)Report a problem with this question

18. 18. In up-and-right gaze, which yoke pair is being tested?

    • A.Right superior rectus and left inferior oblique✓ Answer
    • B.Right inferior oblique and left superior rectus
    • C.Right superior oblique and left inferior rectus
    • D.Right inferior rectus and left superior oblique

    In up-and-right gaze the right eye is abducted, where its superior rectus is the effective elevator, while the left eye is adducted, where its inferior oblique is the effective elevator. Hering's law sends equal innervation to that yoke pair simultaneously, which is why each cardinal position isolates one muscle in each eye and an underaction shows up as a limitation in that specific direction.

    Source: IJCAHPO Core Criteria Handbook, Ocular Motility Testing task list (versions, ductions and muscle functions)Report a problem with this question

19. 19. Which statement describes correct cover testing technique?

    • A.Cover-uncover is done first, watching the uncovered fellow eye✓ Answer
    • B.Alternate cover distinguishes a phoria from a tropia
    • C.Cover-uncover is done first, watching the eye behind the cover
    • D.Alternate cover is done first, watching the covered eye

    Cover-uncover detects a manifest deviation, and it works by covering one eye and watching whether the other, uncovered eye has to move to take up fixation, which it only does if it was already deviated. It has to come first because alternate cover deliberately breaks fusion and reveals the total deviation, phoria plus tropia together, after which the two can no longer be separated.

    Source: IJCAHPO Core Criteria Handbook, Ocular Motility Testing task list (cover tests)Report a problem with this question

20. 20. During the cover-uncover test, the uncovered eye moves outward to pick up fixation. What deviation is present?

    • A.A hyperdeviation, since the eye had been turned up
    • B.An esodeviation, since the eye had been turned in✓ Answer
    • C.No deviation; a normal refixation movement occurred
    • D.An exodeviation, since the eye had been turned out

    The recovery movement runs opposite to the direction the eye was sitting in, so an eye that swings outward to fixate must have been resting inward, which is an esodeviation. Reading the direction backwards is the classic error: an inward movement means the eye was out, and a downward movement means it was up.

    Source: IJCAHPO Core Criteria Handbook, Ocular Motility Testing task list (cover tests and interpretation of refixation movement)Report a problem with this question

21. 21. A patient's nystagmus appears or worsens whenever one eye is covered. How should monocular acuity be measured?

    • A.Occlude the fellow eye and test only at the null position
    • B.Occlude the fellow eye firmly and record the lower acuity
    • C.Fog the fellow eye with a plus lens instead of occluding it✓ Answer
    • D.Measure with both eyes open and record it as monocular

    This behaviour describes latent nystagmus, which is provoked by full occlusion, so covering an eye creates the very movement that then degrades the acuity being measured. Fogging the fellow eye with a high plus lens, or using a translucent occluder, keeps both eyes seeing light and leaves the nystagmus undisturbed, which is why binocular acuity in these patients is often better than either eye tested alone.

    Source: IJCAHPO Core Criteria Handbook, Ocular Motility Testing task list (nystagmus); AAO Ophthalmic Medical Assisting, acuity testing in latent nystagmusReport a problem with this question

Practice questions based on the IJCAHPO core certification content areas for the Certified Ophthalmic Assistant and on standard ophthalmic clinical practice references. COA, COT, and COMT are marks of the International Joint Commission on Allied Health Personnel in Ophthalmology; this site is not affiliated with or endorsed by IJCAHPO. Ophthalmic assistants work under the delegation of a supervising ophthalmologist and permitted tasks vary by state and by practice — confirm your own scope, and check the current exam requirements and content outline with IJCAHPO before testing. About IJCAHPO certification →