Optometrists have issued a warning that virtual reality could be damaging people's eyes as a new study shows that Australians are on the cusp of a VR revolution.
Bupa Optical senior optometrist Karen Makin said there was early evidence linking VR headsets to eye problems but there needed to be more research into long-term use.
"There's not been a lot of research done in the field and that's the concern because it is unknown," he said.
"Virtual reality is wonderful technology and will play a big role in our future, but the reality is that we just don't know yet what the impact it will have on people's eyes in the long run."
The problem with VR headsets, which have been linked to eye strain and dry eye problems, relates to what eye specialists call the "convergence-accommodation reflex".
In the real world, our eyes converge and focus on the same point. In the virtual world the eyes focus on the screen which remains a set distance from the eye but the convergence of objects changes as they move around the virtual space.
"If you're looking at a computer screen, or a smartphone, or a tablet or a book, the eyes are converged so that they're meeting at that distance wherever you're holding it from you and the focus of your eyes is focused at that distance at well, so they're in synch," Ms Makin said.
"But with the virtual reality, the screen is only a short distance."
Makers of virtual reality headsets, including Google, Samsung and Sony, recommend that people only use them for short periods of time, taking a 15-minute break every half an hour and that they are not suitable for children under 12.
Ed Hassall, 39, of Ivanhoe, who has been using a Samsung Gear VR headset for nine months, said he experienced the problems of eye strain and dizziness the first time he dived into virtual reality.
"I remember with my first session, I probably went a bit long and used it for about 40 or 45 minutes. I felt really dizzy and a little bit sick," he said.
Mr Hassall said the immersive experience of VR made it easy to forget about taking regular rests but he tried to restrict his sessions to the recommended time of under 30 minutes to eliminate the eye strain problems and "travel sickness" feelings that can be linked to VR use.
The Telsyte Australian Virtual Reality and Augmented Reality Study 2017 this week shows that 200,000 Australians bought a VR headset in the last year. By 2021, the report predicts a quarter of Australian homes will have a VR headset.
Ms Mankin said vision problems linked to VR headsets were likely to become more common as the technology became mainstream and the content became more immersive.
"Potentially you just get sucked in and before you know two hours is gone and you've stared at this thing for all of this time," Ms Makin said.
She said people using VR should come back to the real world every 30 minutes to rest their eyes.
"In that break I wouldn't suggest you hop on your smartphone or tablet," she said. "Go for a walk out your backyard and do something different."