Ophthalmic Optics 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 flashcards as text
What is the vergence of light rays that are parallel (coming from optical infinity)?
Answer: Zero vergence
Parallel rays from optical infinity have zero vergence because they are neither converging nor diverging.
A lens with a power of -3.00 D will cause light rays to:
Answer: Diverge as if from a point 33 cm in front of the lens
A minus (concave) lens diverges light, with its virtual focal point located at 1/3 m = 33 cm in front of the lens.
Which law states that the angle of incidence equals the angle of reflection?
Answer: Law of Reflection
The Law of Reflection states that when light hits a surface, the angle of incidence equals the angle of reflection measured from the normal.
The index of refraction of a material is defined as the ratio of:
Answer: The speed of light in a vacuum to the speed of light in the material
Index of refraction (n) = speed of light in vacuum (c) divided by speed of light in the medium (v), so n = c/v.
What is the primary optical difference between a plano-convex and a biconvex lens of equal power?
Answer: Biconvex has less spherical aberration
A biconvex lens distributes refraction more equally across two surfaces, reducing spherical aberration compared to a plano-convex design.
When light travels from a medium of lower index to a medium of higher index, it bends:
Answer: Toward the normal
Light bends toward the normal when entering a denser (higher index) medium, as described by Snell's Law.
A prism with its apex pointing upward will deviate a light ray:
Answer: Toward the base (downward)
Light is always deviated toward the base of a prism, so an apex-up prism deflects rays downward.