Which instrument measures the curvature of the surface of a lens? Choose all that apply.

Question

Quizplus · Accepted Answer

The curvature of the surface of a lens can be determined by a using a spherometer, more commonly known as a lens clock.
This instrument measures the base curve of the lens reading the black numbers when all three points are touching the lens.
The inside surface of the lens can also be measured with this instrument. The reading for the inside uses the red markings on the face of the lens clock.
In addition the cylinder of a lens can also be read by reading the inside of the lens, rotating the lens and noting the high and low reading. The difference between the two is the amount of cylinder power in the lens.

Which Instrument Measures the Curvature of the Surface of a Lens