Both eyes are open at all times, but with the stronger eye taking preference and the cue running directly
     Under the chin on the side below the stronger eye.  It does not necessarily apply that a person who is right
     handed is right eyed.  In fact a number of prominent competitors sight with the opposite eye, requiring a
     slightly different stance eg. Professional Graham Miles.

     A test for confirmation of stronger eye, involves holding a sheet of paper with a small hole in the centre,
     in one hand – at arms length, and sighting normally with both eyes open and focussing through the hole at a
     distant object, such as a light.  Then, without moving, alternatively covers each eye with the free hand.  It
     will be found that the pupil will always automatically sight through the hole in the paper with the strongest
     eye.  It should be noted that some competitors claim to aim at all times with both eyes.