So first off we're going to adjust the crosshair.  Going to place the lap jack inside and I'm going to put a box in here for added height and going to turn the knob until the lap jack is nice and clear.  Change the parameter to 200, 4.0 milliseconds or 0.6 millimeters. Do not touch the lap jack and fire the laser.  I am aiming at the little dot on the eye.  As you can see it is not shooting where I the crosshair is.  So the laser did not fire where the crosshairs hit so I'm going to have to adjust where the crosshairs are by loosening up the screw under here and moving the crosshairs over where the laser fired and tightening it back up.  So now we're going to do a test-fire to see if it's lined up going to move it over I'll shoot this eye.  And then fir away and as we can see it hits nice and dead center now the laser is aligned.  So you're going to want to adjust the eye pieces. Close your left eye, adjust the right eye until the lap jack is crisp and clear and you're going to close your right eye and adjust it for your left eye. That will reduce eye strain.