NOCE Cheat Sheet 2026

The 30 highest-yield NOCE facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. Using Prentice's rule, how much prism is induced when a patient looks 8mm below the optical center of a +3.00 D lens? → 2.4 prism diopters
2. Which standard governs the occupational and educational personal eye protection requirements for safety eyewear? → ANSI Z87.1
3. Which contact lens wearing schedule requires the most stringent patient education regarding infection risk? → Extended wear (overnight)
4. A patient's frame is made of memory metal (beta-titanium or Flexon). What is the key advantage of this material for active patients? → It returns to its original shape after bending, reducing breakage
5. Which combination of lens materials inherently blocks UV radiation up to 400nm without requiring an additional UV coating or treatment? → Polycarbonate and Trivex
6. A patient's AR-coated lenses show a persistent greenish or purplish residual reflection. This is MOST likely due to: → The normal residual reflection color of AR coating design
7. Which of the following correctly describes the function of the axis wheel on a manual lensometer? → It rotates the target to align the cylinder axis of the lens
8. What does lag (or lens lag) describe in contact lens fitting assessment? → The movement of the lens in the opposite direction after an eye movement
9. What is the resulting prescription when +1.75 -2.50 x 085 is transposed? → -0.75 +2.50 x 175
10. Which type of multifocal lens design eliminates visible segment lines while providing a smooth progression of power? → Progressive addition lens
11. Which lensometer target pattern indicates that a cylindrical correction is present in the lens being measured? → One set of mire lines clears at a different power than the other set
12. According to the ANSI Z80.1-2020 tolerance standards, what is the allowable tolerance for sphere power for a prescription of -4.75 D? → ±0.13 D
13. In contact lens prescribing, what is the recommended approach when there is a significant amount of residual astigmatism with a spherical soft lens? → Prescribe a toric soft contact lens to correct the residual cylinder
14. OSHA standard 29 CFR 1910.133 requires employers to provide which type of eyewear to employees? → Appropriate eye and face protection for occupational hazards
15. A reverse slab-off is used to compensate for vertical imbalance in a patient with anisometropia. On which lens is a reverse slab-off applied? → The lens with the most plus or least minus power in the vertical meridian.
16. The Abbe number (V) is calculated as V = (nD − 1) / (nF − nC). This formula quantifies: → Chromatic dispersion — higher values mean less dispersion
17. When a spectacle prescription exceeds ±4.00 D in sphere power, back vertex distance becomes clinically significant because: → Small changes in vertex distance produce meaningful changes in effective lens power
18. A patient selects a frame with a very high base curve (e.g., 8 base). Which lens type is BEST suited for this frame? → Wrap-designed or atoric lenses corrected for the tilt
19. Which anti-reflective coating layer is responsible for bonding the AR stack to the lens surface? → Adhesion layer
20. Using the simplified sag formula s ≈ y²/(2r), what is the sag when y = 30 mm and r = 200 mm? → 2.25 mm
21. When using a Burton lamp (UV lamp) to inspect contact lenses with fluorescein, a dark (black) area under a rigid contact lens indicates: → Bearing or touch between the lens and cornea
22. Monocular PD for bifocal segment centration should be measured with the patient: → Looking straight ahead at distance fixation
23. Light diverging from a point source located 50 cm away has a vergence of: → -2.00 D
24. The image formed by a converging lens when the object is placed between the focal point and the lens is: → Virtual, erect, and magnified
25. When using a lensometer to verify prism, the amount of prism is measured by: → How far the target mires are displaced from the center of the reticle in prism diopters
26. Which layer of the cornea is responsible for pumping excess fluid out of the stroma to maintain its clarity? → Endothelium
27. A patient is diagnosed with myopia. This refractive error is primarily caused by which anatomical variation? → The eyeball being too long, causing light to focus in front of the retina.
28. Which of the following correctly describes the role of the 'seg height' measurement in a lined bifocal fitting? → The vertical distance from the lowest edge of the lens to the top of the bifocal segment
29. Which federal agency primarily regulates the manufacture and labeling of prescription eyeglass lenses and frames as medical devices? → Food and Drug Administration (FDA)
30. The ANSI Z80.1 standard specifies that for a single-vision distance lens with a power of -5.00 D, the maximum allowable cylinder power error is: → ±0.13 D