NOCE study guide
NOCE · Work through your exam, one topic at a time.
The National Opticianry Competency Examination (NOCE) is the entry-level certification examination in opticianry administered by the American Board of Opticianry & National Contact Lens Examiners (ABO-NCLE), the body whose site hosts the examination handbooks, testing-center scheduling links, and certification records referenced on this page. Candidates typically sit for it as apprentices, students in opticianry programs, or working dispensers who want a nationally recognized credential, and in some states a licensing board uses ABO-NCLE examinations as part of its requirements. The NOCE study guide has 5 sections and about 1,728 words.
01Ocular Anatomy, Physiology, and Pathology
The tear film (lipid from meibomian glands, aqueous from the lacrimal gland, mucin from goblet cells) is the eye's first refracting surface. The cornea has five layers: epithelium, Bowman membrane, stroma (about 90 percent of thickness), Descemet membrane, and endothelium.
331 words, about 2 min02Optical Theory and Principles
Vergence is 1/f measured in meters, expressed in diopters. Snell's law, n1 sin theta1 = n2 sin theta2, governs refraction at every surface.
353 words, about 2 min03Lens Materials, Designs, and Treatments
Every material choice balances refractive index (thickness), Abbe value (chromatic aberration), specific gravity (weight), and impact resistance. CR-39 has an index near 1.498 and an Abbe value near 58 with excellent optics but poor impact resistance.
341 words, about 2 min04Frame Selection, Fitting, and Measurement
The boxing system measures the lens aperture as a rectangle. A is the horizontal box width, B is the vertical box height, ED is the effective diameter (the longest diagonal), and DBL is the distance between lenses.
359 words, about 2 min05Prescription Analysis, Fabrication, and Verification
Confirm OD and OS, sphere, cylinder, axis, add, prism and base, PD, and any base curve or thickness request. Transposition rule: new sphere equals old sphere plus old cylinder, new cylinder is the old cylinder with its sign reversed, and the new axis is the old axis plus or minus 90 degrees, kept between 1 and 180.
344 words, about 2 min