Researchers have demonstrated how commercially available head-mounted displays (HMDs) can be used to simulate the day-to-day challenges faced by people with glaucoma. Glaucoma is an umbrella term for a group of degenerative eye diseases that affects the optic nerve at the back of the eye. It is the leading cause of irreversible blindness worldwide. Potential applications of the technology could include helping policymakers better assess the impact of visual impairment on patients and helping architects to design more accessible buildings.
Twenty-two volunteers who did not have glaucoma took part in the study. Participants wore a HMD while performing various tasks in either virtual or augmented reality. In the virtual reality task, participants were placed in a simulation of a typical “cluttered” house. Moving their eyes and head allowed them to look around it in order to find a mobile phone hidden somewhere in the house. In the augmented reality task, participants navigated a real-life, human-sized “mouse maze” that they viewed through cameras in the front of the HMD.
Sensors in the HMD tracked the position of each participant’s eyes, allowing the software to generate a blurred area of vision, known as a scotoma, that obstructed the same portion of their visual field wherever they looked. The scotoma was created using medical data from a real glaucoma patient and either restricted vision in the upper part of the participant’s visual field or in the bottom part. In control trials, the scotoma was absent.
Similar to real glaucoma patients, participants were slower to perform the tasks when the simulated impairment was present and made more head and eye movements as well. They likewise found the tasks particularly difficult when the vision loss obstructed the bottom part of their visual field. The results also showed how some people were better able to cope than others with an identical impairment.
The software the team created to simulate the visual impairment, called Open-VisSim, is compatible with most commercially available HMDs and smart phones and supports a range of visual effects designed to simulate the different symptoms associated with a range of eye diseases.