When you get old enough, it doesn't matter about grand theory: you're screwed regardless.
August marks a year where I have had constant battles with tears. The damned things are not in the least emotion-driven: they come of their own volition, make you feel embarrassed even walking down the street, and seriously affect the effectiveness of the drops that have to be applied each day to combat pressure in the eye, quite another problem altogether.
I have been to see the local quack at least six times, have been sent to the hospital twice already, and have a third appointment there on Monday. Except that I don't: due to unending queues at the National Services one, I have been shuttled off to a private hospìtal which has impossible parking. So, as has happened before for the same reason, I will park at the Social Security one and go on a cross-country hike to the city-centre one to see - no pun etc. - if they can do better. Privatised medicine by the back door.
Enjoy your eyes and vision whilst you can; time may come when the iPhone is your only photographic friend.