Due primarily to age, I found it increasingly difficult to wear contacts several years ago because I'm somewhat nearsighted, and while contacts allowed me to see distance well, I actually had to wear reading glasses to use my computer or read a newspaper with them in. It became far more convenient just to wear glasses when needed.
As such, now I need to wear the polarized glasses over my regular glasses when watching 3D movies such as Avatar, and I find that detracts significantly from the movie. What I would like to see is a polarizing film to apply to your regular glasses for watching such movies, or perhaps clip ons (like sunglasses). It would make it much more comfortable for us older (HA!) folks... you know, early 50's...
For that matter, if they can make contact lenses for vision correction, why can't they make contact film for application to sunglasses to do the same? It would sure be more convenient than purchasing prescription sunglasses and probably much cheaper... but that's a different topic.
"Is that a real poncho or is that a Sears poncho?"