- Sit in the middle of the screen at a distance of about 30cm (depending on the size of the screen).
- Enlarge the browser window if necessary so that it fills the whole screen.
- Fix your head (e.g. with one hand) so that it does not move.
- Destroy all enemies! Control the spaceship with the arrow keys and fire a missile with the spacebar.
- Search the screen with your eyes only, your head does not move.
- Work out 2 times a day, each 30 minutes, 5 days a week.
Test this exercise