Classification of severity of visual impairment (WHO).
| Designation according to ICD 10 | Levels according to WHO | Visual acuity with best possible correction |
| Visual impairment | 1 | Visual acuity from 0.3 to 0.1 |
| 2 | Visual acuity from 0.1 to 0.05 | |
| Blindness | 3 | Visual acuity from 0.05 to 0.02 |
| 4 | Visual acuity from 0.02 to light perception | |
| 5 | No light perception |
Severity of visual impairment
| Level | Visual acuity (with best possible correction) | |
| ≤ | > | |
| 0 | 6/18 3/10 (0,3) 20/70 | |
| 1 | 6/18 3/10 (0,3) 20/70 | 6/60 1/10* /0,1) 20/200 |
| 2 | 6/60 1/10 (0,1) 20/200 | 3/60 1/20 (0,05) 20/400 |
| 3 | 3/60 1/20 (0,05) 20/400 | 1/60 (finger counting at 1 m) 1/50 (0.02) 5/300 (20/1200) |
| 4 | 1/60 (finger counting at 1m) 1/50 (0.02) 5/300 (20/1200) | Light perception |
| 5 | Light perception | |
| 9 | Not specified | |
Note for reading the table: the value 1/10 means, for example, that a visually impaired person with 1/10 vision can only see from a distance of 1 m what a person with normal vision can see from a distance of 10 m.
Legend
- Level 0 – no / slight impairment.
- Level 1 – moderate impairment
- Level 2 – severe impairment
- Level 3 – severe visual impairment
- Level 4/5 – blindness
- Level 9 – unspecified impairment.
Blindness in accordance with Section 1 (2) of the Act on the State Blindness Allowance for the Civilian Blind and Section 24 (1) of the Federal Social Assistance Act
As of 01.04.1974, in accordance with § 1 para 2 of the law on the state blindness allowance for the civil blind and § 24 para 1 Federal Social Assistance Act are considered blind in addition to the blind (fully blind),
- No. 1. whose visual acuity in the better eye is not more than 1/50.
- Or in which by No. 1 not only temporary disturbances of vision of such a degree of severity that they are to be considered equal to the impairment of visual acuity according to No. 1.
- Requirements under No. 2 are usually considered to be met if the visual acuity in the better eye:
- Is not more than 1/35, if the visual field of this eye is limited to 30 degrees or further, or 2.2. is not more than 1/20, if the visual field of this eye is limited to 15 degrees or further, or
- Is not more than 1/10 if the visual field of that eye is restricted to 10 degrees or further, or
- Is more than 1/10 to full visual acuity when the visual field of that eye is limited to 5 degrees or further.
