This question-specific review guide is tied to the answer reasoning for a PracticeTestVault item. Use it after you answer the question so the review stays focused on what the prompt actually tested.
What this question is testing
Objective: Lens power and diopters
Prompt focus: The unit used to express the refractive power of an ophthalmic lens is the which of the following?
Why the correct answer works
Diopter
Correct. The diopter is the unit used to express the refractive power of an ophthalmic lens.
Why the tempting wrong answer fails
The tempting wrong answer usually loses because it skips the key condition, priority, or evidence in the prompt.
Plain-language takeaway
The diopter is the unit of refractive power. A lens of one diopter has a focal length of one meter, and power is the reciprocal of the focal length in meters.
Simple analogy
Think of lens power and diopters like following a short checklist: identify the clue, confirm the rule, and then make the move that fits this exact scenario.
How to review it before a retake
- Underline the command word and name what the question is asking before rereading the choices.
- Compare the correct answer against the closest distractor and write the exact detail that separates them.
- Retest this objective with a fresh question without looking at the rationale first.