NLS said:
My near-sightedness is quite bad, I failed the sight-test completely, so the guy at the recruitment office said "You're a danger to yourself and your co-soldiers". I don't care much whether I had to join the military or not, but I can't remember the last time both of my contact lenses fell out and the first thing that occured to me was "shoot myself and all my co-soldiers in panic".
Erm, I don't know in which country you tried to join up in, but in most parts of the western world you get issued with some pretty rugged glasses if you're near sighted. And speaking from a practical standpoint I'd say that trying to use contact lenses in the field would be highly impractical.
You'll most likely get banned from ever becoming a fighter pilot perhaps (since most jet fighters require you to wear a helmet with integrated instruments which is pretty tight so you can't wear glasses under it), but when it comes to foot-slogging infantry work, correctable issues to your sight and hearing would rarely be an issue. (a lot of armies employ people wearing glasses and hearing-aids and they do just fine)
Still, it largely depend on which country you're trying your luck in. Some countries are known to employ rather ridiculous demands on the physical state of the applicant, but this has more to do with some obscure bureaucratic bullshit to do or in other cases that some high-ups in the command structure somehow thinks that a decent soldiers has to be at the peak of physical perfection to be able to do anything at all (which is of course more of a chauvinistic chase after perfection than actual practicality).
You know, kind of how the germans did during WW" with their battletanks. Each had to be a masterpiece of engineering and quality, and sure, many models were some of the most fearsome battletanks ever seen at the time. But it doesn't matter if you have a few superior battletanks when your enemy can churn out several "inferior" battletanks by the hundreds. Your "superior specimens of übermensch goodness" will eventually get swamped and overrun at the end of the day.
The same thing goes for people as well as battletanks. Though some bureaucrats, politicians and parts of the high command hasn't paid much attention to history and practicality, so that's why certtain countries have strange and exaggerated demands on their recruits...