New virtual reality headset reduces eye fatigue, nausea

Researchers have created a prototype for a next-generation virtual reality headset which could reduce eye fatigue and nausea that some wearers experience from currently available headsets.
Virtual reality headsets may leave wearers with a headache or a topsy-turvy stomach because they do not simulate natural 3D images, computational imaging experts say.
Researchers in the Stanford Computational Imaging Group at Stanford University have created a prototype for a virtual reality headset that uses light-field technology to create a natural, comfortable 3D viewing experience.
In current "flat" stereoscopic virtual reality headsets, each eye sees only one image. Depth of field is also limited, as the eye is forced to focus on only a single plane.

In the real world, we see slightly different perspectives of the same 3D scene at different positions of our eye's pupil, said Gordon Wetzstein, an assistant professor of electrical engineering at Stanford.
When you look through a low-cost cardboard virtual reality headset or even a more expensive headset, there is a conflict between the visual cues your eyes focus on and how your brain combines what your two eyes see, called "vergence."

This mismatch is similar to what causes the motion sickness symptoms some people experience. If you read a book in a car, your eyes stay fixed on the text even when the car moves on a bumpy road.

But, because your sense of gravity feels that bumpiness while you read, there is a mismatch between the cues of what you see and what you feel, thus creating the feeling of motion sickness.
The new light-field stereoscope technology - developed by Wetzstein along with researchers Fu-Chung Huang and Kevin Chen - solves that disconnect by creating a sort of hologram for each eye to make the experience more natural.
A light field creates multiple, slightly different perspectives over different parts of the same pupil. This means wearers can freely move their focus and experience depth in the virtual scene, just as in real life.

The headset design incorporates two stacked, transparent LCD displays with a spacer. The researchers' prototype was made with off-the-shelf parts and is the first step toward a viable solution.
Not everyone experiences the negative side effects of current headsets after using them for a few minutes, researchers said.
But solving the problems for longer-term exposures could prove consequential for numerous applications, including robotic surgery, phobia treatment, education and entertainment, they added.