Table 1

 The questions analysed in the study

Questionnaire I
Before cataract surgery
1 Do you have a valid driving licence?
    (a) No, never have had
    (b) No, but I have had one earlier. Go to question 5
    (c) Yes. Go to question 2
2 Do you currently drive a car?
    (a) Yes. Go to question 3
    (b) No. Go to question 5
3 How much difficulty do you have driving during the day because of your vision?
Do you have
    (a) No difficulty
    (b) A little difficulty
    (c) A moderate amount of difficulty
    (d) A great deal of difficulty
4 How much difficulty do you have driving at night because of your vision?
Do you have
    (a) No difficulty
    (b) A little difficulty
    (c) A moderate amount of difficulty
    (d) A great deal of difficulty
    (e) Do not drive because of vision
5 When did you cease driving?
    (a) Less than 6 months ago
    (b) 6–12 months ago
    (c) More than 12 months ago
6 Why did you stop driving?
    (a) Vision too bad
    (b) Other illness
    (c) Other reason
Questonnaire II
After cataract surgery
Questions 2, 3, and 4 from questionnaire I were used
Questionnaire III
5 years after cataract surgery
Questions 1–6 from questionnaire I were used