1. Seat the patient comfortably behind the phoropter with the patient’s distance correction in place.

2. Use a single 20/30 letter on the distance chart.

3. Place the Risley prisms before both eyes and set the prism before the left eye at about 10 to 12 base-in. Set the prism before the right eye at 6 base-down.

1. Instruct the patient to open both eyes and ask how many targets he or she sees. Two targets should be seen.

2. Ask the patient to look at the upper target (seen by the left eye) and keep it clear at all times.

3. Instructions: “I will be moving the lower target up until it is lined up side by side with the upper target. Look at the upper target, keep it clear, and tell me when the lower target moves directly side by side with the upper target.”

4. Move the Risley prisms at about a rate of 2 Δ per second.

5. Record the amount and direction of prism when the patient reports alignment.

6. Repeat the procedure again, using an isolated 20/30 letter or horizontal line of 20/30 print positioned at 40 cm.

1. The patient should wear his or her distance glasses.

2. The patient holds the Maddox rod before the right eye with the striations of the Maddox rod oriented horizontally (patient sees red vertical streak of light).

3. Hold the Thorington card at 40 cm with a penlight behind the center hole of the card.

1. Instruct the patient to look directly at the center of the card.

2. The patient should see a red vertical line.

3. Ask the patient to report the number through which the line is passing and whether it is to the right or left of the zero.

4. For measurement of the vertical phoria, the Maddox rod is held so that the striations are oriented vertically (patient sees horizontal line).

5. Ask the patient to report the number through which the line is passing and whether it is above or below the zero.

1. Control accommodation by reminding the patient to keep the letters on the card clear at all times.

2. This test has been shown to have the best repeatability of the various subjective tests of motor alignment.

3. This test can be valuable for patients who cannot be tested with a phoropter.

1. Seat the patient comfortably behind the phoropter with the patient’s distance correction in place.

2. Use an isolated 20/30 letter or vertical line of 20/30 print positioned at 40 cm.

3. Place the Risley prisms before both eyes and set the prism before the left eye at about 10 to 12 base-in. Set the prism before the right eye at 6 base-down.

1. Instruct the patient to open both eyes and ask how many targets he or she sees.

2. Ask the patient to look at the lower target (seen by the right eye) and keep it clear at all times.

3. Instructions: “I will be moving the upper target from side to side until it is directly above the lower target. Look at the lower target, keep it clear, and tell me when the upper target moves directly above the lower target.”

5. Record the amount and direction of prism when the patient reports alignment.

6. Repeat the procedure, but first add −1.00 lenses OU, in addition to the distance prescription.

1. The patient should wear his or her distance glasses.

2. The patient holds the Maddox rod before the right eye, with the striations of the Maddox rod oriented horizontally (patient sees red vertical streak of light).

3. Hold the Thorington card at 40 cm with a penlight behind the center hole of the card.

1. Instruct the patient to look directly at the center of the card.

2. The patient should see a red vertical line.

3. Ask the patient to report the number through which the line is passing and whether it is to the right or left of the zero.

4. Repeat the procedure, but first add −1.00 lenses OU, in addition to the distance prescription.