Well, when something irritates our nose, a split-second autopilot reflex kicks in causing us to...achoo!
Anyways, it's basically our bodies' way of getting ride of schnoz invaders. The result is that air along with droplets of water and mucus get forcefully puffed out of our mouth and nose.
I'm talking up to 100 mile an hour kind of speed here.
That's quicker than most professional pitcher's fastball. And, hundreds of thousands of microbes might be hitching a ride on that snot train.
So sneezing, is basically is a great way to spread germs and for some people, wires in their brain get crossed, and they end up sneezing at weird moments, like when they pluck their eyebrows or walk into the sun. But, no matter how bad the timing, if you start to sneeze, let her rip because holding on to one has the potential to do some damage including rupturing your eardrums. And yes, it's possible to sneeze with your eyes open, but no, your eyeballs are not going to pop out.
It's a no too that the myth of sneezing stops your heart. Speaking of something not stopping, in 978 days Donna Griffiths holds the record for the longest run of continuous sneezing - you can only hope she bought stock in tissues.