The WHO definition of blindness (used for global burden of disease estimates) is best visual acuity in the better eye, with best correction, of:
- A < 3/60 (< 0.05) ✓
- B < 6/60 (< 0.1)
- C < 6/18 (< 0.3)
- D No perception of light (NPL)
Correct answer: A. < 3/60 (< 0.05)
Explanation
WHO defines blindness as presenting visual acuity worse than 3/60 (0.05) in the better eye. The 2019 updated WHO classification retains presenting VA < 3/60 or VF < 10° as blindness; moderate visual impairment is <6/18 to ≥6/60; severe visual impairment is <6/60 to ≥3/60. India's NPCB historically used < 6/60 with correction as the threshold for programme purposes, but current WHO and IAPB global estimates use < 3/60.
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.