I suffered something similar, just once, about twenty years ago, in high school, and never since. Although, instead of an impression of nothingness, it felt more like a Photoshop content aware fill, similar to the optic nerve blind spot, but moved to the fovea.
I was walking the hall to my first period, mainly looking at the bland floor tiles, and didn't realize anything was abnormal. When I happened to look up at the faces of fellow students, I noticed they had no faces, just skin colored smoothness. My hands, and text on the posters on the walls appeared in my peripheral vision, but as soon as I looked directly at anything, it seemed to disappear into an average of it's surrounding colors. I didn't freak out, but calmly walked to my first period, where I was scheduled to take a test. I made way to my desk, and marveled at this oddness, but didn't say anything, until the test was passed out and I could tell it was a page of text, but, of course, the words disappeared upon inspection. I was really impressed how useless my peripheral vision was in dealing with text or faces.
I had an awkward conversation with the teacher, who I feared thought I'd invented a disorder to get out of the test, before being allowed to visit the nurse.
The condition lasted maybe an hour. The ophthalmologist I saw shortly after found nothing wrong with my retinas or eye pressure, and declared it a visual migraine and let me go, with a newfound empathy for those with macular degeneration.