The LCDVF is a great, affordable viewfinder for DSLR video but the one downside is it doesn’t have a diopter.  Ryan Video Productions discovered a way to modify their LCDVF to add a makeshift diopter using Digital Concepts Macro Adapters.
Via planet5D.
brilliant. 🙂
Another solution is to use a MagnOptx (large) removable lens. They are semicircular, and just need a fraction of their corners cut off to fit neatly in place. Being semicircular they don’t cover the whole surface of the lens, but your vision only uses this centre area anyway.