There may have baan a column or thread on this before, but I couldn’t dig it up, if so, sorry.
But why is tearing at the eyes linked to feeling upset? I was thinking about it the other night, and I can’t think of why flushing your eyes with tears would occur because of a sad movie.
I assumed crying in general, with sobs and wails and other noise, is how parents know their young is in trouble from a distance. I don’t know about the tears, though. Good question!
Is there anything inehernent in vocal cries that would connect it to the tear ducks?
And, for that matter, as I have no clue, do crying babies shed tears?
Hahahaha… okay, sorry. Not tear ducks. Tear ducts.
I read somewhere (sorry, no cite) that they have found that tears contain chemicals which are related to stress. I did a quick google search and found some sites which also say this, but none that I would consider reputable (ie, personal sites, not medical study results)
Thanks for that, I’ll look into that a little.
Anyone one else know anything about it to ease my mind?
Well, my middle school theatre teacher once said that people relieve strong feelings in one of two ways: laughing or crying. This is why some people laugh at very innappropriate times, and others cry when they are happy.
But why would strong feelings cause your eyes to water and tear up? what’e the relation between being sad and having teary eyes?
WAG time: when you are young, crying is your standard response to pretty much any less-than-ideal situation. Tears help clear the eyes of foreign matter, and as our eyes are so vital to us maybe a child under threat automatically 1) bellows for help and 2) begins ‘preventative measures’ to ensure that their eyes are safe (although I guess they could just close their eyes instead…? Maybe they do, but I have no baby on which to check at the moment).
‘Feeling unhappy’ is also a less-than-ideal situation, and even though we can rationalise the fact that there is no physical danger, we are hardwired to respond with the same preventative measures (ie. tears) as we did when we were younger.
Perhaps the tears are to clear the eyes so that vision is clear, which would be needed in either flight or fight. Flight = to see your path as you run, and fight = to see your opponent as you try to fight it off.
This seems a weak theory to me though, I think the tears obscure the vision much more than clearing it. Maybe the tears used to much less in the evolutionary past, and later increased. Of course, then we have almost the same question as the beginning, why so much tearing now?
Torn ducks make the baby Jesus cry.
This site has one answer from a Dr. Mike Marcell, who is (it sez) a research psychologist in Charleston, SC:
There is no reference given for the article Dr. Marcell refers to.
Whacking “why do we cry” into google.com provides a few possible places to begin investigating.
One more 
There is a good article on the BBC science website which has more info, including the facts that 1) babies only begin producing tears when they cry at two months and 2) the tears produced in crying are different to the normal fluid that covers the eyes during the rest of the time.
I had more time to look around based on what I posted earlier and found: