NORTH CAROLINA STATE BOARD OF OPTICIANS
Surfacing and Finishing
- REFERENCES:
- Brooks, C.W. Understanding Lens Surfacing. Butterworth-Heinemann, Boston, 1992.
- Brooks, C.W. Essentials for Ophthalmic Lens Finishing. Butterworth- Heinemann, 2003.
- The North Carolina State Board of Opticians OPHTHALMIC LENS SURFACING and FINISHING examination may include but will not be limited to the following topics:
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- spotting of lenses, lens shapes and patterns;
- centration, blocking, edging, deblocking, hand edging, and tinting of lenses;
- lens insertion and standard alignment;
- drilled, slotted, notched, nylon cord, and other groove mountings;
- how to specify prism base direction;
- bicentric grinding computations and application;
- layout using boxing system;
- base curve selection using applicable tables and formulas;
- minimum blank size calculations;
- the edging process;
- creation of prism;
- use of the lensmeter;
- methods of grinding progressive, Franklin, and other styles of bifocals;
- tool curves;
- lens thickness calculations;
- ANSI Standards;
- methods for handling common ophthalmic materials;
- multifocal lens design;
- lens clock;
- lens and lens blank terminology and standards;
- surfacing procedures;
- power and prism calculations including: computation of nominal and true power, calculating changes in vertex distance for sphere and spherocylinder lenses, calculation of oblique axes power using tables and the sine-squared formula, resultant prism, spherical equivalence, optical power cross, and optical characteristics of ophthalmic lenses.