----------------------------------------------------------------------
| | Additional
Classification | LEVELS OF VISUAL IMPAIRMENT | descriptors
-------------------------------------------------------| which may
| | Visual acuity and/or visual field | be en-
"legal" | WHO | limitation (whichever is worse) | countered
--------|----------|-----------------------------------|--------------
| | |
| | RANGE OF NORMAL VISION |
| | 20/10 20/13 20/16 20/20 20/25 |
| (NEAR-) | 2.0 1.6 1.25 1.0 0.8 |
| NORMAL |-----------------------------------|--------------
| VISION | |
| | 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| Moderate
| LOW | 0.25 0.20 0.16 0.12 | low vision
--------| VISION |-----------------------------------|--------------
| | SEVERE VISUAL IMPAIRMENT | Severe
| | 20/200 20/250 20/320 20/400 | low vision,
| | 0.10 0.08 0.06 0.05 | "Legal"
| | Visual field: 20 degrees or less | blindness
|----------|-----------------------------------|--------------
LEGAL | | PROFOUND VISUAL IMPAIRMENT | Profound
BLIND- | | 20/500 20/630 20/800 20/1000 | low vision,
NESS | | 0.04 0.03 0.025 0.02 | Moderate
(U.S.A.)| | | blindness
| BLINDNESS| Count fingers at: less than 3m |
| | (10 ft) |
| | Visual field: 10 degrees or less |
| |-----------------------------------|--------------
| | NEAR-TOTAL VISUAL IMPAIRMENT | Severe
| | Visual acuity: less than 0.02 | blindness,
| | (20/1000) |
| | |
both | (WHO) | Count fingers: 1m (3 ft) or less |
eyes | | Hand movements: 5m (15 ft) or less| Near-total
| one or | Light projection, light perception| blindness
| both | Visual field: 5 degrees or less |
| eyes |-----------------------------------|--------------
| | TOTAL VISUAL IMPAIRMENT | Total
| | No light perception (NLP) | blindness
--------|----------|--------------------------------------------------
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 field diameter for a 1/100 white test object.

Corneal: