IT’S a party trick that’s bound to get some gasps.
Squirting water out the eye is possible for some – if they blow their nose too hard.
Stick to gentler nose blowing, doctors say Credit: Image Source Plus
Tears are made in lacrimal glands and come out the ducts (inner corner of the eye). Valves (like the lower punctum) take fluid out the eye. But the process can reverse if there is too much pressure, for example when blowing the nose Credit: Getty
But it's not advised to try for risk of infection.
To learn about how it can happen, it’s easier to explain the anatomy of the eye and how tears work.
Tears are made by the lacrimal gland.
There is a main lacrimal gland that sits between the inner eye and bridge of the nose, under the skin, while several others are scattered around the eye.
The glands produce fluid, better known as tears, for various reasons – to cry, to protect our eyes from dust, or to keep the eyes wet.
Fluid drains towards the tear ducts – which are visible to see in the inner corner of the water line – and run down the face.
But it also runs down the back of the nose and throat, which is why you get sniffly when you cry.
There are small openings, called valves, that run inside the edges of the eyelids near the nose.
These are involved with taking tears out of the eyes so that there is not an overflow, draining down small tubes in the bones of the face into sacs, and towards the nose.
The valves can sometimes get blocked, for example when there is an infection, causing excessively watery eyes.
“Some people can experience reflux or overflow through the tear duct,” Dr Michelle Andreoli, an ophthalmologist and clinical spokesperson for the American Academy of Ophthalmology, told LiveScience.
The fluid could also be pushed out by force when there is too much pressure on the valves – such as when you blow your nose.
Anthony L. Komaroff MD, a physician and professor at Harvard Medical School, explained on ShareCare: “Problems can come up when air and fluid go in the opposite direction.
“The small size of the openings and gravity usually prevent this.
“It is sometimes possible to reverse the flow with enough pressure in the nose to force air and mucous back through the lacrimal sac and ducts and into the eye.
“But this is not a good idea. It can force infected mucous into the lacrimal duct and eye, spreading infection.”
He warned: “Stick with the gentle nose blowing.”
Forcing liquid out the eye can also be done using the Valsalva maneuver: Take a deep breath, close the mouth, pinch the nose and then blow out for about 10 to 15 seconds.
Sometimes people do this unintentionally while blowing up a balloon, making their ears “pop” after a flight, playing an instrument, lifting heavy weights or using the toilet.
Some people report squirting milk or blowing smoke through their tear ducts when performing this type of pressure-building maneuver, LiveScience reported.
The smoke – seen in this YouTube video – appears to come from inhaling the smoke of a cigarette before performing the Valsalva maneuver.
Medics say it could also cause a high-pitched sound.
The Valsalva maneuver is typically used as a breathing tool to slow down a racing heart, or normalise blood pressure levels.
It reduces cardiac output, which is the amount of blood that the heart puts out with every beat, so the person doing it may feel lightheaded or dizzy as a result.Internet Explorer Channel Network