iOptics Lab researchers combat VR eye strain with new display method
Julia Sullivan, ECE ILLINOIS
7/3/2017 3:11:31 PM
Virtual reality (VR) and augmented reality (AR) developers promise that the technology is only limited by imagination, but wearing VR goggles for even a short period of time can be challenging. Eye strain, motion sickness, and fatigue are frequent physical complaints that limit the time that can be spent in a VR environment.
According to the pair’s report published in Optics Letters, most current 3D VR/AR displays present two images that the viewer’s brain uses to construct an impression of the 3D scene. This stereoscopic display method can cause eye fatigue and discomfort because of an eye focus problem called the vergence-accomodation conflict.
The two images that make up stereoscopic 3D images are displayed on a single surface that is the same distance from your eyes. But these images are slightly offset to create the 3D effect. Your eyes have to work differently than usual, converging to a distance that seems further away, but keeping your lenses focused on the image that is centimeters from your face. (Learn more about the vergence-accomodation conflict in the Journal of Vision March 2008, Vol.8, 33. doi:10.1167/8.3.33.)
“People have tried methods similar to ours to create multiple plane depths, but instead of creating multiple depth images simultaneously, they changed the images very quickly,” Gao said in an OSA news release. “However, this approach comes with a trade-off in dynamic range, or level of contrast, because the duration each image is shown is very short.”
The researchers are continuing work on the display, increasing power efficiency and reducing weight and size. “In the future, we want to replace the spatial light modulators with another optical component such as a volume holography grating,” said Gao. “In addition to being smaller, these gratings don’t actively consume power, which would make our device even more compact and increase its suitability for VR headsets or AR glasses.”