Venturebeat reports that in order to keep users’ head up, Google placed the Glass display to the upper-right. While this positioning can keep the user from crashing into things, it can also cause sharp eye pain as documented by several users:
— Paul Bilodeau (@deliber8prakts) December 4, 2013
According to Dr. Eli Peli, the Harvard optometrist who consults on ocular discomfort for Google, people almost never actually look to the side with just their eyes for long periods of time. During the setup process and in the first weeks of uses, he says users can look to the side for up to to a minute, sixty times longer than normal, causing eye muscle strain:
It’s not a headache, it’s sort of a discomfort in the eye muscles. To describe it as a headache is inconsistent with how people experience headaches.
Dr Peli says that as the user gets used to the device, the pain goes away for most users after a few days to a week,