While virtual reality (VR) may play a big role not just in the future of mainstream entertainment, but also in industrial and design applications, for some, VR is the harbinger of headaches and nausea. If the researchers from Stanford University get their way, this will not be a problem for much longer.
Currently, virtual reality headsets cannot account for differences in human vision, which can make watching and interacting with virtual reality less enjoyable, or cause headaches or nausea. Now a team at Stanford University's Computational Imaging Lab are working with a Dartmouth College scientist to develop virtual reality headsets capable of adapting how they display images, in order to account for factors like eyesight and age, which affect how people see.
“Every person needs a different optical mode to get the best possible experience in VR,” said Gordon Wetzstein, Assistant Professor of electrical engineering and senior author of the research.
The future, the researchers hope, is VR headsets that offer a personalised viewing experience for users.
The main problem the researchers wanted to solve is the fact that the display screens on VR headsets do not allow human eyes to focus naturally. In real life, our eyes focus on a point, and everything else blurs into the background. Because VR displays are fixed at a certain distance from the eyes, focusing is more difficult, causing eyestrain, discomfort or headaches.
This can become particularly problematic when VR is used over an extended period, such as over a 30- to 40-minute period. This discomfort would be an obstacle for extended interactions with VR content.
Additionally, the visual issues in VR may affect people of different ages in varying ways. People 45 or over often experience presbyopia, where they have difficulty focusing on objects close up. Younger people may not commonly have presbyopia, but may have other vision issues that require the use of corrective glasses. Current VR headsets do not take these vision difficulties into account.
The solution, according to the researchers, is adaptive focus display, a combination of hardware and software fixes which change the focal plane of a VR display.
They tested two different hardware options: one relies on focus-tunable liquid lenses, where twisting a dial squeezes the liquid lenses inside t he headset, changing the screen display even as the lens itself remains in place.
The other option is to mechanically move the display screen back and forth, while also incorporating eye-tracking technology to determine where on the screen the user is looking.
In conjunction with the eye-tracking technology, software ascertains where the person is trying to look and controls the hardware to deliver the most comfortable visual display. The software can account for whether a person is nearsighted or farsighted, though it cannot yet correct for astigmatism.