If you can't see, try falling on your face
We discovered a few weeks ago that the reason Linda doesn't need a prism on her eyeglasses now is because she bent them sometime back by falling on them. She's been trying a different (unbent) pair on from time to time to see how much her double vision is clearing up. I've also straightened her bent glasses a bit at a time for her to make them more straight.
This morning was the first time she could see correctly from her unbent glasses.