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Ervin AM, Boland MV, Myrowitz EH, et al. Screening for Glaucoma: Comparative Effectiveness [Internet]. Rockville (MD): Agency for Healthcare Research and Quality (US); 2012 Apr. (Comparative Effectiveness Reviews, No. 59.)
This publication is provided for historical reference only and the information may be out of date.
| Definition | Snellen Fractions/Decimals | Visual Fields | Clinical Assessment; Count Fingers, Hand Movement, Light Perception |
|---|---|---|---|
| NORMAL VISION | 20/10 20/13 20/16 20/20 20/25 2.0 1.6 1.25 1.0 0.8 | ||
| NEAR-NORMAL VISION | 20/30 20/40 20/50 20/60 0.7 0.6 0.5 0.4 0.3 | ||
| MODERATE VISUAL IMPAIRMENT | 20/70 20/80 20/100 20/125 20/160 0.25 0.20 0.16 0.12 | ||
| SEVERE VISUAL IMPAIRMENT | 20/200 20/250 20/320 20/400 0.10 0.08 0.06 0.05 | Visual field: 20 degrees or less | |
| PROFOUND VISUAL IMPAIRMENT BLINDNESS | 20/500 20/630 20/800 20/1000 0.04 0.03 0.025 0.02 | Visual field: 10 degrees or less | Count fingers at less than 3m (10 ft) |
| NEAR-TOTAL VISUAL IMPAIRMENT | Visual acuity: less than 0.02 | Visual field: 5 degrees or less (One or both eyes) | Both eyes: Count fingers: 1m (3 ft) or less Hand movements: 5m (15 ft) or less Light projection, light perception |
| TOTAL VISUAL IMPAIRMENT | Total blindness No light perception (NLP) |
Visual acuity refers to best achievable acuity with correction.
Non-listed Snellen fractions may be classified by converting to the nearest decimal equivalent, e.g. 10/200 = 0.05, 6/30 = 0.20.
CF (count fingers) without designation of distance, may be classified to profound impairment.
HM (hand motion) without designation of distance, may be classified to near-total impairment.
Visual field measurements refer to the largest