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Categories of severity of visual impairment according to the International Statistical Classification of Diseases [1]. |
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| Category of visual impairment |
Visual acuity with best possible correction |
Or central visual field* |
Classified as |
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| Maximum less than |
Minimum equal to or better than |
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| 1 |
6/18 3/10 (0.3) 20/70 |
6/60 1/10 (0.1) 20/200 |
Low vision |
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| 2 |
6/60 1/10 (0.1) 20/200 |
3/60 1/20 (0.05) 20/400 |
Low vision |
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| 3 |
3/60 1/20 (0.05) 20/400 |
1/60 (finger counting at 1 metre) 1/50 (0.02) 5/300 (20/1200) |
10° or less but more than 5° |
Blindness |
| 4 |
1/60 (finger counting at 1 metre) 1/50 (0.02) 5/300 |
Light perception |
5° or less |
Blindness |
| 5 |
No light perception |
Blindness |
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| 9 |
Undetermined or unspecified |
Unspecified |
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*Visual field restriction criteria applicable even if visual acuity is better than for that category of visual impairment. | ||||
Dandona and Dandona BMC Medicine 2006 4:7 doi:10.1186/1741-7015-4-7 |
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