| Value | Category | Cases | |
|---|---|---|---|
| 1 | no difficulty seeing | 8396 |
95.6%
|
| 2 | some difficulty | 290 |
3.3%
|
| 3 | a lot of difficulty | 90 |
1%
|
| 4 | cannot see at all | 2 |
0%
|
| 8 | don't know | 1 |
0%
|
| Sysmiss | 4170 |