Is it normal to have intermittent aversion to looking at protruding angles?

My brothers and I all experience this. Every now and then, we have a spell (lasting maybe 5-10 minutes) when it is almost painful to look at protruding angles, like corners. Often this happens when we already have a headache, but not always. When it does happen, we usually have to just sit with our eyes closed and hold our heads until it passes.
The sensation is difficult to describe. It's as if, when we look at a corner, we feel it prodding at our brain. Our sister has never experienced this and thinks it is abnormal.