Do I need to stop wearing contact lenses before ICL surgery?

Wearing contact lenses can affect the measurements of the corneal curvature.
The type of contact and how you were them determines how long you should stay out of them. This is why back up glasses are so important!
For those in soft contacts who don't sleep in them, 3-7 days should be fine. I prefer 7 to be safe.
For those who sleep in soft lenses or wear gas permeable lenses, I would recommend no less than 3 weeks in glasses alone.