Wikipedia's Guide for Opticians

Wikipedia provides useful information to introduce you into the optician profession.
http://en.wikipedia.org/wiki/Optician

(1) Learn more about the history
(2) How to Become a Licensed Optician in the United States

You may also want to visit the Optician Forums to meet other people in the profession. The forum also have many visitors that are not opticians so that you can get an idea of what kind of questions you may be expected to answer as an optician.

How to Use a Lensometer

A lensometer is the instrument used to measure an eyeglasses prescription. As an optician, you will be responsible for checking the accuracy of prescriptions as well as reading prescriptions from eyeglasses that customers already own.

View the video "Using a Lensometer to Check Glasses" to view the basics of using a lensometer.