Have you thought about informing your mono vision client that to experience the full 3D forms in films, you need both eyes with full distance correction.
To learn more about 3D, I have found a video on YouTube that explain how it works
This is what I use as an alternative correction possibility.
• Glasses that have 0D. in the dominant eye and -add in the none dominant eye.
• Alternative sale of one day lenses to the none dominant eye so the client can put on when needed.
• Of course is the multifocal lenses the third alternative.