http://health.asiaone.com/Health/News/S ... 53042.html

I think it is due to a lack of peripheral awareness, because when there is a lack of light then the peripheral framing is not unconsciously enough, and thus you "don't know where to look" in the central vision field, because the eyes cannot synchronize as the frame is too bad, you need to switch on the peripheral awareness to get rid of the strain within the frame.