By Tamara McLean
Rubbing the eyes has been proven to contribute to conditions like glaucoma and short-sightedness, but eye specialists have discovered many other basic behaviours also increase risk.
"Yoga head stands, weightlifting, sleeping face down, playing instruments like the trumpet and swimming laps are some of the many ways of causing eye pressure spikes," said Professor Charles McMonnies, from the University of New South Wales School of Optometry and Vision Science.
"Pressure spikes are fine if you have healthy eyes. But all the people out there with these conditions, and so many others at risk of them, can be negatively affected, and many don't know it."
Glaucoma affects more than 300,000 Australians, causing blindness as the disease progresses, while rapidly increasing myopia, or short-sightedness, affects almost one in five people.
Prof McMonnies tested the effects of eye rubbing and compared the pressure effects with other activities in a paper published in the journal Optometry and Vision Science.
He found eye rubbing caused the biggest spike, raising pressure to ten times normal levels, but may be only an occasional harmless event.
The literature review found the risk may be higher for activities carried out regularly and for long periods, like wearing goggles while swimming lengths.
People who play a high wind-resistance instrument like a trumpet, oboe, French horn or bassoon, especially when they play high-pitched notes, can more than double their eye pressure.
Weight-lifting from a bench, doing sit ups on a slant board or upside down poses in yoga also increase pressure, Prof McMonnies said.
Sleeping face down was another major contributor that most people were unaware of, he said.
"Avoiding sleeping with the eyes in contact with a pillow or sleep mask may help to slow the progression of pressure-sensitive eye diseases," the specialist said.