What would happen if you smoked marijuana, if you have a gas bubble in your eye from retinal surgery?

Poor Positioning. A gas bubble in your eye is usually placed to be positioned over and close retinal holes and keep the retina attached. This requires positioning and i would not recommend any substance that might alter your mind and ability to maintain the proper position to fix your retina.
Not much. As long as you don't lose control of yourself from getting high on todays new and improved marijuana, you will do not harm to an eye with a gas bubble inside.