(All) The one difference you will all notice is that between the ages of 50 and 55 (or thereabouts) you will lose the ability to change the focus of your eyes. Regarding your eye as a camera, you could say that the lens is still quite clear and forms sharp images, the film is more-or-less as good as it was, but the focussing mechanism will seize up and there is nothing whatsoever you can do about it except get reading glasses.

[Rosie] You're lucky if you noticed it that late... most people do in their 40s, though it depends on what they do, and how long their arms are :-)

It's at least 43°C, dusty outside and dry as a bone... I think I'm starting to look forward to my holiday...

(flerdle) My knuckles graze the floor. This of course is why I play the trombone. Where are you, for it to be 43°C? Not Oz, at this time of the year, surely? A pleasant 18°C here. Sun in and out. Light breeze. Very British.

Oman.