I definitely remember cheap green-phosphor CRTs that took a second or more to fade from full-brightness to zero-brightness. If you tried to strobe a pixel back

I definitely remember cheap green-phosphor CRTs that took a second or more to fade from full-brightness to zero-brightness. If you tried to strobe a pixel back and forth it would just look full brightness because it didn't have enough time to visibly fade before being turned on again.