Re wearing eye protection.
A friend of mine had an accident in a PA28. The windscreen broke into shards of Perspex and he had multiple small cuts on his face. The prescription glasses he was wearing were also damaged. He assesses that if he hadn't been wearing glasses, then he might well have lost the sight of at least one eye. He was a licenced aircraft engineer and a very experienced pilot. The lesson? In a light aircraft, ALWAYS wear some form of eyewear. clareprop above has a bit of a tongue-in-cheek look at what the military wear. They don't wear all that to look cool, but to protect themselves from injury.
Now, anyone over 40 probably needs to wear some form of eyesight correction whilst flying. Even if their distance vision is still good, then their close vision will have lost its 'accommodation' as the lens muscles seize up. My advice to them is NOT to wear half-moon specs but to invest in varifocals with no correction in the upper part, grading down to a reading prescription in the lower part. Of course, your medical will require you to carry a spare pair. Why not choose a second pair with a tint for brighter days? I've been wearing varifocals for flying for 25 years and at my age can still read a map, the instruments and spot traffic miles away without having bits of spectacle frame in the way. (A new lens in one eye helps a lot, too!)
I find many people who had good vision in their youth are 'in denial' about wearing specs, thinking they're somehow geeky and not cool. Get over it.
I appreciate the issue about spectacle side frames and headsets, I suffered with this when I first started. I now choose titanium frames that are extremely thin and frameless lenses and don't notice them at all under my Lightspeed Sierra.
Re headgear.
The pilots who concern themselves most with lookout fly gliders. They've developed the 'beany' hat which whilst keeping the worst of the sun off your head (they are invariably white) permit unobstructed vision as far as possible. So-called baseball caps and the like with a pronounced peak do nothing for your lookout. Beany hats look a bit silly and wearers of baseball caps think they look good (not my opinion!) but in the cockpit, what matters more, being able to avoid traffic or thinking yourself 'with it'?
TOO