FREE ABO-NOCE Prescription Transposition Questions and Answers

Question 1

Transpose the following prescription into plus cylinder form: +1.50 -2.00 x 090

Accepted Answer

-0.50 +2.00 x 180

Answer

To transpose, first combine the sphere and cylinder powers to get the new sphere (+1.50 + -2.00 = -0.50). Second, change the sign of the cylinder (-2.00 becomes +2.00). Third, change the axis by 90 degrees (90 + 90 = 180).

Question 2

Transpose the following prescription into minus cylinder form: -3.00 +1.25 x 170

Accepted Answer

-1.75 -1.25 x 080

Answer

To transpose to minus cylinder, first find the new sphere by adding the sphere and cylinder (-3.00 + +1.25 = -1.75). Next, change the cylinder sign (+1.25 becomes -1.25). Finally, change the axis by 90 degrees (170 - 90 = 080).

Question 3

What is the spherical equivalent of the prescription +2.25 -1.50 x 120?

Accepted Answer

+1.50 D

Answer

The spherical equivalent is calculated by adding half of the cylinder power to the sphere power. In this case: +2.25 + (-1.50 / 2) = +2.25 + (-0.75) = +1.50 D.

Question 4

Transpose the prescription Plano +2.50 x 030 into minus cylinder form.

Accepted Answer

+2.50 -2.50 x 120

Answer

Start with the sphere (0.00) and add the cylinder (+2.50) to get the new sphere: +2.50. Change the cylinder sign to minus: -2.50. Change the axis by 90 degrees: 30 + 90 = 120. The result is +2.50 -2.50 x 120.

Question 5

Which of the following prescriptions is optically identical to -1.00 -1.00 x 045?

Accepted Answer

-2.00 +1.00 x 135

Answer

To find the optically identical prescription, you must transpose the original. New sphere: -1.00 + (-1.00) = -2.00. New cylinder: +1.00. New axis: 45 + 90 = 135. The transposed prescription is -2.00 +1.00 x 135.

ABO NOCE Basic Opticianry Practice Test

ABO NOCE Basic Opticianry Practice Test

FREE ABO-NOCE Prescription Transposition Questions and Answers