The intial battery of tests involved the usual glaucoma test, eyesight testing, and - less usually - flashes of bright lights. Eventually the eye doctor worked through lens options and determined what I needed. One of my eyes is slightly better, one is slightly worse. In neither case is it a major change. At the end of the appointment, she showed me the results of those flashes of bright lights: photos of the backs of my eyes.
As someone who's been generally of good health, I've had very few chances to see imaging of my insides in my life. This is a good thing. It was fascinating to see the alien, organic spheres aglow on the monitor which were the backs of my eyes, complete with veins, arteries, and the end of the optic nerve. Blown up, each took up the entire screen.
It was an unexpected development in my life's history of eye exams. But so was the one that followed: the doctor emailed me the photos.