Wearing Two Pairs of Glasses at the Same Time

I was watching Schitt's Creek with my wife last night (more like binge watched) when this scene with the talented Catherine O'Hara came up:

Her character, Moira, came in from the outdoors wearing her sunglasses and went to use the computer when she found out some distressing news. She flipped her sunglasses on to the top of her head and slapped on her reading glasses. Fortunately, there's a modern day solution to this dilemma. 

Rather than constantly having to switch from your sunglasses to clear a clear pair when you walk indoors, Transitions, changeable lenses activate to the environment. It's like having two pairs of glasses in one. The lenses are clear indoors and turn dark outdoors. No switching back and forth between two sets of glasses. For these folks, Transtions, Photochromic reading glasses give the ability to be worn indoors and outdoors.

I've seen people switch from reading glasses to distance glasses too. Often times, people will remove their readers so they can look at something in the distance. A set of bifocals allows one to see near and far. Again, no need to switch between glasses.

Why not combine the best of both worlds and have bifocal glasses that are clear indoors and turn dark outdoors?

By the way, if you haven't seen the show, it's very funny!