Lensometry

Question 1

A patient’s prescription from a referring doctor is written in minus cylinder notation, while your ophthalmologist works in plus cylinder. Transpose the following prescription:
+2.25 -0.75 x 165, +3.75 -1.25 x 003

A. +1.50 +0.75 x 75, +2.50 +1.25 x 093
B. +1.50 +0.75 x 165, +2.50 +1.25 x 003
C. +1.50 -0.75 x 165, +2.50 -1.25 x 003
D. -1.50 +0.75 x 075, -3.75 +1.25 x 093

Answer 1

A. +1.50 +0.75 x 75, +2.50 +1.25 x 093

Question 2

On the back of a frame are a few figures such as 46 x 22. What do these numbers represent?

A. Bridge and lens size
B. Pupillary distance and segment height
C. Lens and bridge size
D. Segment height and pupillary distance

Answer 2

C. Lens and bridge size

Question 3

What is the ONLY accurate method for measuring pupillary distance?

A. Pupil gauge
B. Light reflex method
C. Ruler
D. Dark reflex method

Answer 3

B. Light reflex method

Question 4

A lens with the focal length of 2 meters has a power of

A. 0.50 D
B. 1.00 D
C. 2.00 D
D. 5.00 D

Answer 4

A. 0.50 D

Question 5

What part of the spectacle frame connects the two lenses?

A. Temple
B. Cover
C. Rim
D. Bridge

Answer 5

D. Bridge

Question 6

The measurement used to determine the distance between the optical centers of spectacle lenses is the

A. pupillary distance
B. axial length
C. vertex distance
D. refractive error

Answer 6

A. Pupillary distance