Vanishing act

One night when I was a teenager, during a break from playing keyboards in a nightclub, I was staring at a brick wall in a hallway much like this:



It had a carriage lamp on it but nothing else. As I stared directly ahead at the wall—but not the lamp—the lamp gradually disappeared so that all I saw was an unadorned brick wall:



I have since been able to do this at will with other scenes. It doesn't work if I stare at the object that I'm trying to erase, and the background has to be uniform, either solid or patterned. I just look at it for a few seconds and the object fades from view. if I alter my gaze, the object comes back.

I know that we all have a blind spot where the optic nerve passes through the back of the eye ball and that our brain compensates by filling in the details based on the scene. Maybe that facility is erasing the lamp. Somehow, I am able to consciously control it. Has anybody else had this happen to them?