nm010
General information
Question text: | How long does each episode of the darkening or graying out of vision last? |
Answer type: | Radio buttons |
Answer options: | 1 Few seconds 2 A few minutes 3 Ten to 60 minutes 4 A few hours 5 Longer than 24 hours 6 I don't know |
Label: | how long each episode of darkening or graying out of vision last |
Empty allowed: | One-time warning |
Error allowed: | Not allowed |
Multiple instances: | No |