Equipment Opticians who dispense use a variety of equipment to fit, adjust and dispense eyewear, contact lenses and low vision aids.
The dispensing of eyewear requires the use of a lensometer to verify the correct prescription in a pair of eyeglasses, to properly orient and mark uncut lenses, and to confirm the correct mounting of lenses in spectacle frames. Certain lensometers also have the ability to examine contact lenses.
The parameters appraised by a lensometer are the sphere, cylinder, axis, add, and in some cases, prism. The lensometer is also used to check the accuracy of progressive lenses, and is often capable of marking the lens center and various other measurements critical to proper performance of the lens.