NOCE / ABO Basic study guide
NOCE / ABO Basic · Work through your exam, one topic at a time.
The ABO Basic certification, administered through the American Board of Opticianry and National Contact Lens Examiners (ABO-NCLE), is the entry-level credential for opticians in the United States. It signals that a dispenser has demonstrated a broad working knowledge of ophthalmic optics and the practical tasks of the trade - reading a prescription, selecting and fitting eyewear, verifying finished lenses, and adjusting a frame to a patient's face. The NOCE / ABO Basic study guide has 10 sections and about 2,777 words.
01Ocular Anatomy, Physiology, and Refractive Conditions
The eye has two refracting elements: the air–cornea interface supplies roughly two-thirds of total power (about 43 D of the eye's ~60 D), and the crystalline lens adds variable power through accommodation. Know the anterior corneal radius (~7.8 mm), corneal index (1.376), the anterior chamber and aqueous (produced by the ciliary body), the vitreous, and the layered retina with the fovea as the point of highest acuity.
282 words, about 1 min02Geometric and Physical Optics
Vergence is L = n / l, with l in meters; light diverging from a point 0.5 m away in air carries −2.00 D of vergence. A thin lens of focal length f (meters) has power F = 1/f.
301 words, about 2 min03Prescription Analysis and Lens Power Calculations
A prescription lists sphere, cylinder, axis, prism, add, and sometimes base curve and PD. Sphere corrects all meridians equally; cylinder corrects the difference between meridians and must be paired with an axis from 1 to 180.
283 words, about 1 min04Lens Materials, Designs, and Treatments
Key numbers: CR-39 is n = 1.498, Abbe ≈ 58, specific gravity ≈ 1.32. Crown glass is 1.523 with Abbe ≈ 59, but heavier and less impact resistant.
287 words, about 1 min05Frame Types, Materials, and Frame Measurements
Full-rim metal and plastic, semi-rimless with nylon cord, rimless/drill mount, and combination frames, plus hide-a-bevel, grooved, and wrap styles. Metals include monel, nickel silver, stainless steel, aluminum, titanium, and beta-titanium (light, corrosion resistant, shape memory).
303 words, about 2 min06Eyewear Fabrication, Finishing, and Verification
Surfacing runs through generator, fining, and polishing, then coating; edging, mounting, and adjustment follow. Layout positions the optical center or major reference point in the frame relative to the pupil and segment height.
273 words, about 1 min07Frame Adjustment, Repair, and Dispensing
Four-point alignment means the frame front is straight, temples are parallel to each other and perpendicular to the front, and both temples touch a flat surface simultaneously. Check x-ing (crossed temples), vertex distance (commonly 10–14 mm, near 12), pantoscopic tilt (about 8–12°), face form or wrap (about 5°), and the frame front's horizontal and vertical alignment.
272 words, about 1 min08Standards, Safety, and Regulatory Compliance
ANSI Z80.1 covers prescription ophthalmic lenses, including tolerances for power, axis, prism, thickness, and impact resistance. ANSI Z87.1 covers occupational eye and face protection; the complete device must be tested, and frames and lenses carry manufacturer markings plus the high-impact "+" designation where applicable.
249 words, about 1 min09Contact Lens Fundamentals
Contact lenses are described by base curve, diameter, power, material, and center thickness. Hydrogels (low and high water content) and silicone hydrogels transmit oxygen; Dk is permeability and Dk/t is transmissibility, the clinically meaningful figure.
256 words, about 1 min10Patient Service and Optical Business Practices
Build a repeatable routine: greet the patient, verify prescription and history, identify visual tasks, explain options in plain language, confirm benefits and cost, then dispense with care instructions and follow-up. Set adaptation expectations for progressive lenses and high-index materials, and explain cleaning, warranty, and service terms.
271 words, about 1 min