The first step in using a lensometer to check glasses is to?

Question

Quizplus · Accepted Answer

The first step in using a lensometer to check glasses is to calibrate the eye piece for you.
To calibrate, set the focus wheel to plano. Then turn the eyepiece counterclockwise as far as it can go. Carefully, as you are looking in the eyepiece, turn the eyepiece back slowly until you see the target mire is clear and focused. Note where the index spot is and use this setting each time you use the lensometer.
This is done because you may have a slight eye error, which will affect the way you see the mires in the lens.

The First Step in Using a Lensometer to Check Glasses