We've all heard the rumour, but what would actually happen if you sneezed while keeping your eyes open? Nothing? Or would your eyes pop out of your head?

Firstly, you have to think about how the eye works. There are six different muscle groups holding the eye in place: the medial and lateral rectus; the superior and inferior oblique; and the superior and inferior rectus muscles. These all help you move your eyes around when trying to see.

So you have six muscles, as well as your eyelids, helping you keep your eyes in place when sneezing, and yet, most of us can't help but to close our eyes when we sneeze anyway.

But thanks to the few people who don't experience the urge to close their eyes when they sneeze, we know that the way our eyes are held in place prevents a sneeze from popping them out. That said, there are other ways to lose your eyeballs.

In a 2006 case study from the Netherlands, a man with floppy eyelids reported that his eye had dislodged from its socket several times in three months. 

IJO-60-324-g001Ashok Kumar / Indian Journal of Ophthalmology 2012

There have also been reports of people experiencing their eyes popping out - called luxation - in traumatic accidents, or by putting in their contact lenses wrong. There have been cases of people losing eyes in car accidents and on the sporting field. We couldn't find any cases of bungee jumpers experiencing luxation, but don't try to block your nose and mouth while trying to exhale - people have accidentally popped their eyes when attempting this.

It's important to note that having your eyes pop out for whatever reason is a very unlikely scenario, and is usually due to an underlying condition. In fact, only four cases of random luxation were documented between 2002 and 2010.

The eye also usually doesn't fall completely out of the socket - it just dislodges and pops forward, giving you (or your doctor) the opportunity to push it gently back into place.

And while we're dispelling sneezing myths, what about the myth is that a sneeze is equivalent to an eighth of an orgasm? Unfortunately, just like the eye-popping myth above, this isn't true either, but it's easy to see how the myth came about.

Sneezes and orgasms are both reflexes involving muscle tension and release, and there is some evidence that both a sneeze and an orgasm releases endorphins.

But, scientifically speaking, it's safe to say that an orgasm and a sneeze are two very different things, and that you probably won't lose your eyeballs if you do manage to sneeze with your eyelids open.