Just to back up what I said before. Before I applied for my Transport Canada medical I email them to ask what the current situation was. In my email I stated that I was over both the stated diopter and uncorrected vision limits.
This is the reply I received:
---
Mr Crawford,
Canada is in the process of removing the diopteric limits from the vision
standards, so provided you can correct your distant vision to 6/9 ( 20/30
) in each eye separately and 6/6 using both eyes, then we would consider
you fit for all medical categories
Sincerely
XXXX
---
Furthermore I do now hold a full class 1 medical despite having worse than -5 correction in both eyes, and pretty bad uncorrected vision. So I can confirm that what the gentleman from TC told me is correct - as long as you can be corrected to 20:20 using both eyes, you can be class 1 certified.
The -3.5 thing is a thing of the past.
Cheers,
Andrew