Refraction: astigmatism: practice question

A Ophthalmology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Ophthalmology · Refraction: astigmatism

Sample item

What optical abnormality causes regular astigmatism?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

D. Different refractive power in different corneal meridians

Regular astigmatism arises from unequal curvature of corneal or lenticular meridians, producing different focal planes. Cylindrical correction compensates for this meridional difference.

Option by option

  • A. Inflammation of the iris

    Iritis causes painful photophobic red eye.

  • B. Loss of retinal blood supply

    Retinal ischemia is a vascular disorder.

  • C. Complete absence of a lens

    Absence of lens is aphakia.

  • D. Different refractive power in different corneal meridians (correct)

    Correct. Unequal meridional power creates astigmatism.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

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Questions about this Ophthalmology question

What is the answer to this Ophthalmology question?

The best answer is D, Different refractive power in different corneal meridians. Regular astigmatism arises from unequal curvature of corneal or lenticular meridians, producing different focal planes.

Why is "Inflammation of the iris" not the answer?

Iritis causes painful photophobic red eye.

Why is "Loss of retinal blood supply" not the answer?

Retinal ischemia is a vascular disorder.

Why is "Complete absence of a lens" not the answer?

Absence of lens is aphakia.

What concept does this question test?

It tests Refraction: astigmatism in Ophthalmology. Cylindrical correction compensates for this meridional difference.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Refraction: astigmatism?

Group the red eye by what to examine and what the pupil does. Then use the flashcards and the other Ophthalmology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.