You don't have to worry about moving your eye. Modern lasers can adjust the operation to eye movements. The position of the eye is evaluated with a special camera in microsecond intervals and the controlling system of the laser always moves the healing ray so that it hits the right place of the cornea. If the eye gets wholly outside the operational area of the laser (for example, due to rapid movement of the head), the operation of the laser is discontinued. The doctor will adjust the position of your head and the procedure can go on.