Kingsman 2: the eyepatch on harry's glasses

This is a model of eyepatch that can be on glasses like in the movie Kingsman: The Golden Circle (in the glasses of harry)
WARNING!
The part have to be bigger than the glasses. So follow the instructins below:
1. Print the part one time.
2. Try to put the part on your glasses (don't push it too strong) If it can fit skip to 6. If it can't fit (or too big) go to 3.
3. Calculate what is the proportions you need.
4. Print again with the new scale.
5. Try to put the part on your glasses again