A 22-year-old student complains of blurred vision in the right eye. Uncorrected visual acuity is 6/36. With a pinhole held before the eye, acuity improves to 6/6. This finding indicates that the cause of reduced vision is most likely:
- A Refractive error ✓
- B Macular pathology
- C Optic nerve disease
- D Early cortical cataract
Correct answer: A. Refractive error
Explanation
The pinhole allows only central paraxial rays to reach the retina, effectively neutralising refractive error, so improvement to normal acuity localises the problem to the optical/refractive system and predicts good corrected vision. Macular and optic nerve lesions produce genuine retinal or neural dysfunction and do not improve with a pinhole. Cortical cataract may show variable response but characteristically does not normalize fully, and glare testing rather than pinhole discriminates it best.
Reference: Parsons' Diseases of the Eye, 23rd ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.