Refractive Errors & Methods of Correction MCQ Quiz | Refraction & Binocular Vision

1. A 25-year-old patient’s prescription is -5.00 D sphere. Where does parallel light focus in his uncorrected eye?

2. Latent hyperopia, which is masked by the tone of the ciliary muscle, is best revealed by:

3. A stenopaeic slit improves a patient’s vision to 6/6 when held vertically, but remains poor when held horizontally. This clinical finding is indicative of:

4. The primary physiological cause of presbyopia is:

5. During LASIK (Laser-Assisted In Situ Keratomileusis) surgery, the flap is typically created from which corneal layers?

6. A convex lens brings parallel rays of light to a focus at a distance of 25 cm. What is the power of this lens?

7. A serious and vision-threatening complication most commonly associated with overnight wear of soft contact lenses is:

8. Following the surgical removal of the crystalline lens (cataract surgery without IOL implantation), the eye is said to be aphakic. What is the typical refractive state of an aphakic eye?

9. A patient with a prescription of OD: +1.00 DS and OS: +4.00 DS has significant anisometropia. Contact lenses are often a better corrective choice than spectacles in such cases to avoid:

10. The sudden displacement of an image, known as “image jump,” experienced by wearers of bifocal lenses when their line of sight crosses the segment line is primarily caused by:

11. Which of the following is the most characteristic sign of keratoconus observed during retinoscopy?

12. Photorefractive Keratectomy (PRK) differs from LASIK primarily in that it involves the mechanical or alcohol-assisted removal of which corneal layer before laser ablation?

13. In a spectacle prescription of -2.00 / -1.50 x 180, what is the total dioptric power at the 90° meridian?

14. The physiological process of accommodation, allowing the eye to focus on near objects, is achieved by the contraction of the ciliary muscle, which is innervated by:

15. The most common underlying cause of simple and pathological myopia is:

16. Toric soft contact lenses are specifically designed with different powers in different meridians to correct which refractive error?

17. A patient wears a -10.00 D spectacle lens at a vertex distance of 12 mm. To achieve the same refractive correction with a contact lens (vertex distance = 0 mm), the required power would be approximately:

18. The main optical disadvantage of progressive addition lenses (PALs) compared to traditional bifocals is the presence of:

19. Which uncorrected refractive error in early childhood is most likely to cause bilateral refractive amblyopia (lazy eye in both eyes)?

20. The Jackson Cross Cylinder (JCC) is an essential tool used during subjective refraction primarily to refine the:

21. Phakic Intraocular Lenses (IOLs) are a surgical option for correcting high refractive errors. Their key characteristic is that they are:

22. In against-the-rule astigmatism, the meridian with the steepest curvature (and thus, the most refractive power) is:

23. The principle behind Orthokeratology (Ortho-K) for the correction of myopia involves:

24. In mixed astigmatism, the two focal lines are located on either side of the retina. For the best possible uncorrected vision, the circle of least confusion should ideally be located:

25. The principal refractive surface of the eye, contributing the most to its total refractive power, is the: