Phorometric Tests

Question 1

What is the endpoint sequence recorded in convergence at far testing?

Answer 1

Blur / Break / Recovery
➡️ If no blur occurs: Record as X / BR / R
✅ Example: X / 20 / 6

Question 2

How are values determined in Test #10 (BO prism)?

Answer 2

Add the prism values from the right and left rotary dials at each endpoint.

Question 3

What is the expected order of values in convergence testing?

Answer 3

Break > Blur
Recovery < Break
➡️ Recovery can sometimes be lower than blur if accommodation is disrupted.

Question 4

If patient does not report diplopia in VT #10, but reports image movement, suspect theres ___

Answer 4

suppression

Question 5

if Right eye is suppressed, the image direction in VT 10 is

Answer 5

Rightward movement

Question 6

if image in VT 10 has Leftward movement, what is the suppressed eye

Answer 6

left

Question 7

What should be done if suppression is suspected during Test #10?

Answer 7

Stop test when movement is reported
Record as suppression
Identify suppressed eye based on direction
Sum of prism in both eyes at the point of report = test result

Question 7

if Right eye is suppressed, the image direction in VT 10 is

Answer 7

Rightward movement

Question 8

if image in VT 10 has Leftward movement, what is the suppressed eye

Answer 8

left

Question 9

What patient reference tool is used for reporting image movement?

Answer 9

Use clock orientation to help the patient identify movement direction accurately.

Question 10

Why is there no blur point in vertical vergence testing?

Answer 10

Because vertical prisms do not stimulate accommodation, so only break and recovery points are expected.

Question 11

What is considered a normal vertical fusional reserve at distance and near?

Answer 11

Typically, 2–3∆ break point, and 1–2∆ recovery in vertical fusional reserves is considered normal.

Question 12

What prisms are used in Tests #12 and #18 for vertical phoria measurement?

Answer 12

A 6∆ base-up prism over the left eye (measuring prism) and 12–15∆ base-in prism over the right eye (dissociating prism).

Question 13

To determine the presence and magnitude of vertical phoria and evaluate vertical fusional vergence reserves at distance (6m or 20ft).

Answer 13

VT 12A

Question 14

To determine the presence and magnitude of vertical phoria and evaluate vertical fusional vergence reserves at near

Answer 14

VT 12B

Question 15

What patient reference tool is used for reporting image movement?

Answer 15

Use clock orientation to help the patient identify movement direction accurately.

Question 17

What condition is indicated if the patient requires a high amount of base-up or base-down prism to achieve alignment?

Answer 17

A hyperphoria or vertical deviation, which may suggest a muscle imbalance, such as a superior oblique or inferior rectus dysfunction, or underlying systemic/neurological issue.

Question 18

vertical phoria testing, if the patient reports the top image is to the left, which eye is likely hypo?

Answer 18

The left eye is hypo, meaning it is lower than the right eye.

Question 19

What clinical conditions can induce vertical phorias?

Answer 19

Systemic illnesses (e.g., cold, sinus infection), neurological issues (e.g., stroke, cranial nerve palsies), and toxic conditions.

Question 20

is the latent vertical deviation under dissociation;

Answer 20

vertical phoria

Question 21

refers to vertical fusional vergence ability to overcome that phoria.

Answer 21

vertical duction

Question 22

It is the maximum amount of accommodation (focusing power) the eye can exert, measured in diopters (D)

Answer 22

amplitude of accommodation

Question 23

How is amplitude of accommodation commonly measured?

Answer 23

Using the push-up test, push-down test, or the minus lens method.

Question 24

What test number in the OEP 21-step phorometric test corresponds to amplitude of accommodation?

Answer 24

Test #19

Question 25

What is the normative data for amplitude of accommodation according to Hofstetter’s average formula?

Answer 25

15 – (0.25 × age) (in diopters)

Question 26

What test number in the OEP 21-step phorometric test corresponds to amplitude of accommodation?

Answer 26

Test #19

Question 27

What is Hofstetter’s minimum expected amplitude of accommodation formula?

Answer 27

15 – (0.3 × age) (in diopters)

Question 28

What is Hofstetter’s maximum amplitude of accommodation formula?

Answer 28

25 – (0.4 × age) (in diopters)

Question 29

What is the clinical endpoint in the push-up amplitude test?

Answer 29

The closest point where the patient reports the target is still clear before blur occurs.

Question 30

What is a limitation of the push-up method for measuring AA?

Answer 30

It may overestimate AA due to magnification of the target at close distances.

Question 31

What condition is characterized by a reduced amplitude of accommodation for age?

Answer 31

Accommodative insufficiency

Question 32

In the minus lens method, what is added to the final result to estimate true amplitude?

Answer 32

Add 2.50D to compensate for the fixed testing distance of 40 cm (16 inches).

Question 32

What is a limitation of the push-up method for measuring AA?

Answer 32

It may overestimate AA due to magnification of the target at close distances.

Question 32

What condition is characterized by a reduced amplitude of accommodation for age?

Answer 32

Accommodative insufficiency

Question 33

What is the preferred clinical method for AA in presbyopic patients?

Answer 33

The minus lens method, done at 40 cm using minus lenses until blur is reported.

Question 34

In the plus lens method, what is deducted to the final result to estimate true amplitude?

Answer 34

deducted to 2.50 diopters to get the amplitude of accommodation.

Question 35

For non-presbyopic patients, what is the endpoint when performing the minus lens method for AA?

Answer 35

When the patient reports that the print is difficult to read or constantly blurry, despite increasing minus lenses.

Question 36

Why is adding minus lenses preferred in testing amplitude for presbyopes instead of immediately adding plus?

Answer 36

To determine the exact limit of the accommodative effort remaining by forcing the system to exert maximum accommodation before confirming blur.

Question 37

To assess accommodation posture (lead or lag) without convergence involvement by dissociating the eyes.

Answer 37

Dissociated Cross Cylinder (Test #14A)

Question 38

What lenses are used during Dissociated Cross Cylinder testing?

Answer 38

Typically, a ±0.50D Jackson Cross Cylinder (JCC) lens is used, oriented at ±90°, over each eye.

Question 39

What is the endpoint of the DCC test?

Answer 39

The plus or minus lens at which the vertical and horizontal lines appear equally clear — indicating neutral accommodation (neither lead nor lag).

Question 40

What does a preference for horizontal lines during DCC testing indicate?

Answer 40

A lag of accommodation, requiring plus lenses to neutralize.

Question 41

Is the DCC test monocular or binocular?

Answer 41

It is dissociated binocular – both eyes are open, but binocular fusion is prevented by dissociation.

Question 42

What does a preference for horizontal lines during DCC testing indicate?

Answer 42

A lag of accommodation, requiring plus lenses to neutralize.

Question 42

What is the key difference between BCC and DCC?

Answer 42

BCC is a fused binocular test (no dissociation), while DCC is dissociated. BCC evaluates accommodation under normal binocular conditions.

Question 43

What is the endpoint of Binocular Cross Cylinder (Test #14B)?

Answer 43

The amount of plus lens at which the horizontal and vertical lines appear equally clear, showing the patient's binocular accommodative posture.

Question 44

Why is BCC preferred over DCC for tentative near addition determination in presbyopes?

Answer 44

Because it assesses natural binocular accommodation, making it clinically more relevant for determining near add power.

Question 45

What is the expected BCC result for a young patient with normal accommodation?

Answer 45

A small plus lens (+0.25 to +0.75D) indicating a normal accommodative lag.

Question 46

What could a negative value or minus lens endpoint in BCC indicate?

Answer 46

A lead of accommodation, which is usually abnormal, or over-minus in the distance prescription.