Ophthalmic Optics Questions and Answers Flashcards
7 cards from real ABO NOCE Basic Opticianry practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Ophthalmic Optics Questions and Answers flashcards as text
A prism displaces light toward its:
Answer: Base
Light bends toward the base of a prism, while the image appears displaced toward the apex.
In the spectacle magnification formula, which factor relates to the power of the lens?
Answer: Power factor
The power factor component of spectacle magnification accounts for the vergence-changing effect of the lens power.
Which of the following best describes the term 'vergence' as used in ophthalmic optics?
Answer: The curvature of a wavefront of light
Vergence describes the degree of convergence or divergence of a wavefront and is measured in diopters.
The nominal power of a lens is calculated using which formula?
Answer: F = (n₂ - n₁)/r
Surface power is calculated as F = (n₂ - n₁)/r, where n values are the refractive indices and r is the radius of curvature in meters.
When a convex lens is placed in contact with a concave lens of equal but opposite power, the result is:
Answer: A plano (zero power) lens
Equal and opposite powers cancel each other out, resulting in a lens system with zero net power (plano).
The critical angle for total internal reflection depends primarily on:
Answer: The refractive indices of both media at the interface
The critical angle is calculated using sin(θc) = n₂/n₁, depending on the refractive indices of both materials at the interface.
Which lens form produces the least oblique astigmatic error for a given prescription?
Answer: Corrected curve (best form)
Best-form (corrected curve) lenses are designed with base curves that minimize oblique astigmatic error for each prescription power.