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Free clinical optics practice questions for optometry and ophthalmology students, residents, and trainees preparing for NBEO and OKAP. Cover retinoscopy, keratometry, lensometry, spherical equivalent, Prentice's rule, vertex distance, the duochrome and pinhole tests, and Jackson cross cylinder — every question includes a clear explanation so you actually learn as you go.
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Sample question 1
Explanation
In regular astigmatism, the two principal meridians are perpendicular to each other. This makes the refractive error amenable to correction with cylindrical lenses.
Sample question 2
Explanation
The effect of vertex distance on effective lens power increases as lens power increases. For this reason, accurate vertex distance is especially important in high ametropia.
Sample question 3
Explanation
Transposition changes the cylinder sign to its opposite and rotates the axis by 90 degrees. The sphere is also adjusted by adding the original cylinder power.
The optics quiz draws from the full OcuQuiz optics bank. Each of the topics below has a dedicated lesson with a board-focused walkthrough — great to review before or after your quiz attempt.