| Value | Category | Cases | |
|---|---|---|---|
| 1 | no difficulty seeing | 3915 |
96.5%
|
| 2 | some difficulty | 110 |
2.7%
|
| 3 | a lot of difficulty | 31 |
0.8%
|
| 4 | cannot see at all | 2 |
0%
|
| 8 | don't know | 0 |
0%
|
| Sysmiss | 8891 |