NORTH CAROLINA

STATE BOARD OF OPTICIANS

SURFACING & 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, FINISHING examination may include but will not be limited to the following topics:

• 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.