Scientists from the University of California in San Francisco (UCSF) have discovered that Google Glass can cause the wearer's peripheral vision to be partially obstructed. If this is the case, the wearer may have difficulty in performing activities such as driving, running and cycling.

When the wearer's peripheral view is obstructed, it creates a far larger blind spot which is worse than those that are caused by wearing normal glasses. The most affected area where one's vision is obscured is the upper right hand side, the side where the Glass' digital display and camera are situated.

The study was participated by three people who had to wear Google Glass for 60 minutes to get used to the spectacles. The device was then turned off and the participants were asked to do a vision test known as the perimetric visual field test. This will check if they had any 'blind spots' on that part of their vision which was obstructed. It included checking their peripheral vision which is what can be seen outside the center of one's sight.

Afterwards, the participants did the same vision test wearing ordinary glasses of similar shape and color. The results are then compared by the researchers.

The researchers also performed an Internet search where they looked for photos of people who are wearing the Glass and facing the camera. They studied the way that the Glass sits on people's faces, whether there's a chance that the device is interfering their vision.

They learned that the prism of the Glass obstructed vision in the wearer's upper right hand corner which is also referred to as the 'superior-temporal quadrant.' However, the regular glasses brought little impact.

"The superior-temporal quadrant is particularly important in driving as the location of the rear-view mirror as well as the right-side mirror in all U.S. cars is monitored by the right visual field," says Dr. Edward Koo, a clinical ophthalmologist at the UCSF. "Motion detected in these mirrors by a normal peripheral visual field is what frequently alerts a driver to possible dangerous situations."

The same hazard is also faced by drivers in the U.K. where the blockage of the driver's right peripheral vision may even create a bigger threat to public safety.

He added that the right peripheral field is important when doing other activities that would require one to perceive hazards and obstacles such as jogging or cycling on the road.

The researchers stressed that wearing the Glass can have a negative impact on the wearer's right peripheral vision which can create safety issues both to the wearer and to those around them. They plan to conduct a larger study to further assess their findings.