That's not how optical scanning works (Score 3, Insightful)

I used to have a TV and its vertical yoke died one day. When messing with the potentiometers in the back to try to adjust the picture back to a working state, I quickly discovered that the electron beam that scans the inside of the picture tube is extremely strong and produces a very bright spot on the screen.

When you think about it, though, the phenomenon makes a lot of sense. The beam is as bright as (average pixel brightness) * (total pixels on the screen). If you concentrate the brightness of the entire screen on one point, that point is going to be very bright and may well be damaged.

And that brings us to the problem here. If you burn the phosper off a little dot on your TV's picture tube, it's not the end of the world - you can just buy a new TV. But if you burn a spot in your retina, it's there forever unless you can get an eye transplant. If you used such a low-power laser or electron beam that this wouldn't happen, your picture would be too dim to see.

Mr. Uptime