In minus-lens accommodative testing, what extra diopter value must be added to the final calculation regardless of testing distance?

In minus-lens accommodative testing, what extra diopter value must be added to the final calculation regardless of testing distance?

• A. 0.50 D
• B. 3.00 D
• C. 2.50 D
• D. 1.25 D

Answer: (C)

In minus-lens accommodative testing, you must include a working-distance compensation to translate the measured accommodative response to the actual demand at the near target. This compensation is the reciprocal of the testing distance, added to the final calculation. The protocol for this test uses a near target at 40 cm, so the compensation is 1/0.40 = 2.50 diopters. This value is added to the final result regardless of the other testing distances because it standardizes the adjustment for the near-working distance. Therefore, 2.50 D is the additional diopter value used.

In minus-lens accommodative testing, you must include a working-distance compensation to translate the measured accommodative response to the actual demand at the near target. This compensation is the reciprocal of the testing distance, added to the final calculation. The protocol for this test uses a near target at 40 cm, so the compensation is 1/0.40 = 2.50 diopters. This value is added to the final result regardless of the other testing distances because it standardizes the adjustment for the near-working distance. Therefore, 2.50 D is the additional diopter value used.