General Practice 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 General Practice flashcards as text
A patient's prescription reads +2.50 -1.00 x 090. What is the spherical equivalent?
Answer: +2.00
Spherical equivalent = sphere + (cylinder/2) = +2.50 + (-0.50) = +2.00.
Which frame measurement represents the longest horizontal dimension of a single lens aperture?
Answer: A measurement (eye size)
The A measurement is the horizontal width of one lens opening in the frame.
Prentice's Rule states that prismatic effect (in prism diopters) equals:
Answer: Power (D) × decentration (cm)
Prentice's Rule: Δ = P(D) × d(cm); decentration must be expressed in centimeters.
When transposing a minus-cylinder prescription to plus-cylinder form, the new axis is:
Answer: Original axis ± 90°
Transposition to the opposite cylinder form requires rotating the axis by 90 degrees.
A frame marked 54-18-140 has what bridge size?
Answer: 18 mm
In standard frame notation (eye size–bridge–temple length), the middle number (18) is the bridge width.
What is the primary purpose of selecting a base curve for a spectacle lens?
Answer: To minimize peripheral aberrations and fit the frame design
Base curve selection is guided by the need to minimize oblique astigmatism and other off-axis aberrations.
Which condition is characterized by reduced near vision due to decreased accommodative amplitude associated with aging?
Answer: Presbyopia
Presbyopia is the age-related loss of accommodation that reduces the ability to focus at near distances.