I just realized I may have a use case for myself. I have been 2-3km out on the lake on my OC1 with my phone in a waterproof case and strapped to the boat. It's there for absolute emergencies, and I would not dare take it out. A waterproof smartwatch could actually be useful to me, especially if I could take/make a call.

Most likely this was a procedure to measure the thickness of your cornea at various points. I had this done prior to and after my corneal transplant.