Concentration Meditation leading to Tetris Effect

Has anybody noticed this? The Tetris Effect ( en.wikipedia.org/wiki/Tetris_effect ) is when you spend a lot of time focusing on one activity such that your mind becomes obsessed with it. For example, you might dream about it, or see things about it with your eyes closed, etc. This used to happen to me sometimes when I was coding for too long.

Recently, it seems to be happening really often. I just started playing this Scrabble game, haven't even really been into it so much, but when I close my eyes I see scrabble tiles everywhere, rearranging themselves in a grid. When I played Fruit Ninja on the iPhone, I'd see blobs going up in my vision and I'd catch myself imagining how to cut them down. Has anyone else noticed this becoming more prevalent? It's kind of funny, not really important, but an interesting curiosity nonetheless.

I suppose that's how kasina is supposed to work in the traditional instructions, where you stare at the object until you can "see" it with your eyes closed.

Obsession with meditation-related things is also a common feature of the A&P territory.