White or black glitches are our 'souls' momentarily seperating from our concious being from this fluid reality. Our concious bodies recognise this
change imperically. Bodies arent great devices for encapsulating one's soul.
Glitches in this percieved reality pertain to this experience
I'm the same age as you and remember experiencing the same thing about that time. I can't say exactly when it was or even how many years ago, but I
can definantly say I was in middle school (which would fit your timing) and that others noticed it as well. At the time I assumed that the lights had
flickered (a lot of our rooms didn't have windows, or had windows but the teachers kept them covered).