Having two eyes is extremely important to us, it enables our brains to calculate the relative distance of the various objects around us, providing depth perception.
This can prove deceptive, however, since we tend to assume that our perception of the world is relative to the middle of our eyes, but this is rarely true. Almost all of us have one eye stronger than the other, a dominant eye. When we determine the relative positions of objects and their angles, especially as they get closer to us, the brain tends to accept the point of view of the dominant eye. Even with both eyes open, the information from our dominant eye is given priority.
Knowing which eye is dominant, and how this effects our perception, is very important for golfers since it can help us to avoid some of the mistakes, the illusions, that can influence our body positions, club alignment and aim. We discuss two of these illusions in Golf Swing 503 – Downswing: The Great Golf Impact Illusion and Putting: The Vertical Shaft Illusion.
Make a circle with your thumb and first (index) finger. With both eyes open look at an object in the distance, such as a flag, and centre it inside the circle – see Figure 1. Now close each eye in turn.
When you closed one of your eyes you should have found that the object jumped outside the circle, a phenomenon known as parallax – see Figure 2. If the object seemed to move when you closed your left eye, then you have left eye dominance. If the object moved more when your right eye was closed, then your right eye is the dominant one. In Figure 2 the flag jumps left because the viewer is right-eye dominant.
The object you chose was initially lined up to be in the circle using information from your dominant eye. When you close this eye you can see that the object was not lined up for your other, non-dominant, eye.
About 80% of the population are right-eye dominant, and a very small percentage seem to have no eye-dominance at all.
Whenever you are checking your aim or alignment, or the positions and angles in your setup, you should always remember that you are using your dominant eye to do so, and you are not seeing the world from the midline of your body.
In Figure 1, for a right-eye dominant player, the golfer’s hand and the flag are lined up with their right eye, not with the middle of their body. A shot played on that line from the middle of the golfer’s body would miss left.
For example, when you are standing with the middle of your head directly behind a putt, if you are right-eye dominant then you are seeing the line from slightly to the right of centre. The imaginary line that you see as being from the ball to the middle of the cup is actually pointing slightly left of the cup! To correct this, you need to line up with your dominant eye in line with the ball, and not the middle of your head – and it may help to close your non-dominant eye just to be sure.