I had cataract surgery on my right eye many years ago.  The Docs replaced the bad lens with an artificial one, and I’ve had 20:20 distant vision in that eye ever since.  Meanwhile, a cataract in my left eye has been getting worse.  That eye still works, especially up close when I leave out its contact lens that corrects for distant vision.  In effect, without wearing the contact and then wearing the specs that then correct both eyes for up-close vision, I have usable vision without needing to bother with the contact or the glasses.  

So, around my apartment, I seldom need to wear the contact or my glasses.  Since my right eye with its 20:20 distant vision was the corrected one, it had long been my habit to use that eye to peep through the spy-hole in my apartment’s front door to see who or what lurked on the other side.  The result was a blurry but usable view.  I’m not sure why, but one day last fall I used my cataract-dimmed left eye to peep through the spy hole.  Wow!  What a difference!  With that seemingly worse left eye, things were now much clearer.  Somehow, when the optics of the lens in the door’s spy-hole was combined with my cataracted left eye and its usable up-close vision, I could see more clearly.  What a pleasant, useful result from such a simple change in behavior.

The lesson for me was in learning that changing my behavior in this small way (switching eyes) resulted in a definite improvement.  Are there any other old dogs out there who could improve things a bit by changing their behavior a bit?