Is Eye Dominance Real in Tennis?

What do we really know about how the eyes work in tennis?

There is now a widespread belief in the tennis coaching world that eye dominance, where one eye is assumed to be preferred over the other for sighting, plays an important role in tennis biomechanics. But is it true and/or helpful?

The theory of ocular dominance states eye dominance should be tested and incorporated into tennis technical development decisions. But there is significant controversy about this subject. Not all coaches agree about the importance of eye dominance and many sport scientists and eye experts question the validity of the connection between eye dominance and technique.

Two highly successful coaches, Jofre Porta and Patrick Mouratoglou, plus professional trainer Paul Dorochenko, are examples of experts in the tennis world who believe in the dominant eye theory. But the question is whether it is real or myth.

This article investigates the basis for the ocular dominance theory, compares and contrasts the views of leading sport vision experts and tennis coaches. The next article will offer sensible advice on how to incorporate vision training into the Winning Pretty philosophy and approach.

Dr. Daniel Laby, one of the experts I consulted.

According to the opinion of Daniel Laby, MD, a former assistant professor at Harvard University and an expert in sports vision who has consulted for numerous Major League Baseball teams, vision can be trained and improved using modern science and computer technology. Dr. Laby, author of the new book, Eye of the Champion, has developed an extensive computer testing protocol to help athletes improve their sports vision.

According to Dr. Laby, the eyes should be trained according to the following priorities:

Fundamental vision health and monocular performance related to acuity and contrast sensitivity
Binocular stereo vision depth perception
Neural processing and visual decision making
Visual integration using visual mechanics
On field/court vision exercises and training

OK, but what does all that mean for tennis? Dr. Laby and his colleague David Kirschen, PhD, believe that tennis players should focus on improving binocular vision—meaning both eyes working together--and they should deprioritize any focus on a single dominant eye.

Image Courtesy of Dr. Daniel Laby

Kirschen also consults for MLB teams and earned his PhD in physiological optics from Cal Berkeley. He and Laby have published extensively on ocular dominance in sports. They believe that the dominant eye does not have an effect on performance in sports like tennis.

Drs. Laby and Kirschen make three primary arguments about the dominant eye:

Dominant eyes are not the same as dominant hands in function or physiology
There are many field tests for eye dominance, some with average to good reliability but most with poor validity.
Most athletes, including tennis players, should focus on using binocular vision and ignore the dominant eye altogether.

It's important to delink the entire conception of eye dominance and hand or hemispheric dominance, according to Laby and Kirschen. They argue that the eyes are meant to work together using binocular vision and that the theoretical construct of eye dominance is rooted in a misunderstanding of how the eyes work dating back 500 or so years.

Their argument is that the eyes are organs designed to be receptors of information while the main function of the hands and arms are "effectors."

David Kirschen, key collaborator with Daniel Laby.

The limbs are lateralized in the brain, but the eyes send information to both sides of the brain. Any prioritization of eye dominance training or technical adjustments according to eye dominance miss the mark because the eyes should be trained to work together bilaterally for optimum performance.

While the hands are often required to work at different tasks simultaneously or individually, the eyes are designed to capture input and send the information to the brain together, like a team. A lack of understanding of the fundamental structural difference between the limbs and eyes explains the fallacious reasoning seen in the field by coaches and professionals alike.

Furthermore, Drs. Laby and Kirschen argue that many of the field tests used by coaches to test for eye dominance are inherently flawed, leading to misdiagnoses. Sighting tests like the Miles test, or the "hole in the card test," are good examples of a commonly used but flawed tests.

This classic sighting test involves looking at an object with the hands raised up together creating a triangle to look through. According to research cited by Dr. Laby, the results of sighting tests can vary based on arm fatigue or injury.

Laby and Kirschen also note that test results can vary based on the distance of the target object. Additionally, research shows that sighting tests can give different results depending on the angle of the target object's position in the visual field.

The popular Miles test, which involves sighting a distant object between a triangle made with the hands, forces a yes/no answer in terms of eye dominance and does not allow for different levels of dominance and cases of non-dominance, which is a rare but real occurrence in the population. Drs. Laby and Kirschen recommend using more precise computer tests that offer gradations in measuring eye dominance rather than just a left or right eye dominant answer.

Dr. Don Tieg, another well known vision expert.

But those tests whatever the flaws and results are probably totally irrelevant.Dr. Laby states that in sports like tennis and baseball, binocular vision is critical and that visual acuity, contrast sensitivity, and depth perception are higher priorities than eye dominance.

Tennis requires strong long-distance acuity, contrast sensitivity and depth perception that can all be trained. The dominant eye used for sighting, if there is one, should not be a significant factor in tennis performance.

Dr. Don Teig is another expert on sports vision who has worked with numerous professional athletes. Teig agrees with Laby that tennis athletes should focus on stereovision using both the eyes to get the best possible depth perception.

For Teig, however, the dominant eye still plays a role in sports vision. Teig cites one Canadian study that shows a 14 millisecond difference in processing speed for the dominant eye. "It may not seem like a lot of time, but 14 milliseconds is very important in sports like tennis and baseball where athletes need to track a ball at high velocities," asserts Teig.

Teig recommends always having the dominant eye closest to the incoming ball to maximize information processing and signaling to the muscles to react. But Teig agrees with Laby that binocular vision with both eyes facing the ball is paramount in a sport like tennis and more important than focusing on the dominant eye.

Experts like Laby and Teig focus on many other areas of sports vision to improve performance and deemphasize the role of the dominant eye in sports like tennis and baseball. Here are some commonly tested sports vision components that are important to tennis other than the dominant eye:

A general ocular health assessment to ensure the health of the eyes.
Static visual acuity, which is how well the eyes see at a distance when an object is not moving. Most people are familiar with this type of testing at their regular eye doctor checkups. Ensuring 20/20 vision or higher is important and can improve acuity when objects are moving, meaning depth perception and accommodative accuracy. Most elite athletes actually have much better vision than 20/20, some better than 20/10.
Dynamic acuity is an important measure of how well the eyes see a moving target.
Contrast sensitivity, which describes how the eyes process information in different light conditions and with different backgrounds.
Depth perception is another crucial aspect of eye performance, and both Teig and Laby emphasize the importance of using both eyes to enhance stereovision (using both eyes) in depth perception.
Ocular alignment describes the location of the eyes according to retinal image disparity and affects object locating.
Peripheral awareness and split attention, which describe the vision outside of centralized focus and how well the eyes can track multiple objects at the same time.
Speed of recognition—how quickly the eyes see information is very important to tennis athletes.
Visual to motor reaction time. New technologies allow testing of the speed at which visual neural impulses reach the brain and motor neuronal impulses are sent to the muscles to move the body.
Visual approaching anticipation, which is how quickly the eyes see an object approaching the individual.

Of course the average or even elite player will rarely be examined or tested on these criteria so let's move on to the central debate in coaching: what role if any does eye dominance have in coaching and what does the Tennisplayer high speed video archive reveal about eye dominance coaching claims?

What role if any should eye dominance play in stroke development?

In contrast to the experts like Drs. Don Teig, Daniel Laby and David Kirschen, coaches in the tennis world continue to promote eye dominance as a major factor in technique and performance. According to Jofre Porta of Spain and Patrick Mouratoglou of France, eye dominance is an important factor when teaching or learning technique.

American coach Nick Saviano also believes that technique can be influenced by eye dominance. Porta and Mouratoglou have made "laterality," or the study of dominance in the brain and human body, an integral part of their teaching philosophies.

They argue that the way a player sees the ball can affect how players move their head, how much they turn their shoulders, and which stances they prefer on certain shots. For example, according to Jofre, a player who is right eye dominant and right-handed may turn less in the preparatory phase of the forehand, use a more semi-open or open stance, open the body more to face the incoming ball pre-impact, and may rotate the head during the swing, and all compensations like this help to track the ball better with the dominant right eye.

For Jofre, trying to build technique without considering eye dominance will lead to frustration and misunderstanding.

Patrick Mouratoglou concurs and advises adjusting stances and head position to maximize vision with the dominant eye. Mouratoglou is one of the most famous professional coaches in the world. He believes eye dominance can affect many areas of a player's technique including their stance, trunk rotation, head position, and contact point.

The "dominant eye" should dictate stances and head position, according to famed coach Patrick Mouratoglou.

According to Mouratoglou, by watching top players and the way they set up their stances, shoulder turn, head position, and their contact points, he can often determine their eye dominance just by observing. He believes coaches should actively adjust player technique based on their dominant eye.

Mouratoglou produced a video entitled, "Your Dominant Eye and Your Technique" that went viral in 2023. Because Mouratoglou has promoted the dominant eye theory so publicly, it has become one of the most interesting and important topics in modern tennis technique. But, unfortunately, more and more people are talking about the dominant eye now with less and less scientific underpinning.

Mouratoglou makes many claims regarding the dominant eye and tennis technique. According to Mouratoglou, the dominant eye plays a tremendous role in technique, not just in tennis but in all sports. He says that the dominant eye relays information more accurately than the non-dominant one, with profound technical implications.

Says Mouratoglou, "The neurons respond preferentially to information from one eye versus the other. This means the neurons in your arms, legs, and hands respond preferentially to the information received from your dominant eye, and head position can affect how the dominant eye processes information."

Do players really have more shoulder rotation on the eye dominant side?

Eye experts disagree about the veracity of this statement: Don Tieg agrees, while Daniel Laby does not. For Mouratoglou, it is essential for tennis players to position the body so as not to block the dominant eye and to leverage the accuracy of the dominant eye for ball tracking because the non-dominant eye sees the ball less accurately with a small displacement, causing the body to be in the wrong position to receive the ball.

Tieg agrees with this assertion while Laby says it's important not to block either eye, while focusing on binocular vision. According to Mouratoglou, blocking the dominant eye in tennis is why some players feel less comfortable hitting on one side of their body, either the forehand or backhand side.

Mouratoglou argues that champion tennis technique is always influenced by the dominant eye. "These champions tend to have one side with a bigger shoulder rotation, a more lateral contact point, and a strong transfer. Contrarily, the opposite side has less shoulder rotation, a contact point more in front, and less transfer through the ball.

This weaker side uses more "wrist action" to compensate for these differences," states Mouratoglou. But in the Tennisplayer High Speed Archive the turns seem exactly the same for both sides.

Patrick Mouratoglou also states that cross-dominance, when the dominant eye is opposite the dominant hand, affords a special advantage in tennis. According to Mouratoglou, players like Roger Federer and Rafael Nadal are famous cross-dominant professional players who have incredible forehands, partly due to their cross-dominance.

The contact point appears the same for so-called cross dominant players.

Dr. Teig is one expert who agrees with Mouratoglou that cross-dominance is an advantage in baseball and tennis, while Drs. Laby and Kirschner do not. For example, for right-handed players with left eye dominance, Patrick says these athletes can have a bigger shoulder rotation and yet still have great perception of the incoming ball, which means these players are typically in the best position to receive the ball.

This is the first advantage of cross-dominance. The second advantage of cross-dominance is that the larger shoulder turn in the preparation for cross-dominant individuals means more power on the forehand, presumably from a greater degree of separation between shoulders and hips. The larger trunk rotation gives the player more power on this side, according to Mouratoglou.

The third advantage of cross-dominance is that the contact point for cross-dominant players is more lateral, generally between the legs, according to Mouratoglou. Mouratoglou argues that this later contact point allows for more contact time for the strings on the ball during impact, helping to give more control and power to the shot.

Players like Roger Federer and Rafael Nadal demonstrate these three advantages in their forehands, according to Mouratoglou. Mouratoglou also states that cross-dominant players like Roger Federer are very dangerous running to their forehand side because they can see and track the ball with their dominant eye when running laterally. Don Tieg accepts that this may be true.

Mouratoglou describes common characteristics of same-side dominant players such as Alexander Zverev. He says that for same-side dominant players like Zverev, their best shot is generally the backhand. According to Mouratoglou, same-side dominant players have a shorter shoulder rotation on the forehand to ensure their head fully faces the net and their dominant right eye can track the ball.

At the impact, right eye/right hand dominant players will open their shoulders more to the net with their chest facing the ball more at impact than cross-dominant players do and they will tend to use semi-open to open stances to promote better ball tracking with their right eye.

Mouratoglou argues that same-side dominant right handed players tend to have much better backhands than forehands as compared to cross-dominant individuals because they can watch the ball more accurately with their dominant eye while turning more deeply with the shoulders, meet the ball later in the impact zone, and keep the shoulders semi-turned through the impact.

They can turn very deeply on the backhand and still have a good perception with the dominant right eye. The deep turn provides these players with more power from trunk rotation, states Mouratoglou.

According to Mouratoglou, the later contact point and semi-open shoulder position favors a long passage through the ball, bringing both power and accuracy on the backhand side. Same-side dominant players can hold the ball on the strings longer for better power and control, asserts Mouratoglou.

Jofre Porta: another famous coach who believes in eye dominance.

Jofre Porta has been using the dominant eye in his coaching method for decades. Porta has coached two number one players in the world from Spain, Rafael Nadal and Carlos Moya, and many of the top juniors in Spain as well as having a loyal following of international students, especially Russians and Eastern Europeans.

He is a frequent educational speaker around the world at International Tennis Federation events. Coach, educator, and philosopher, Jofre supports his theories with an eclectic range of sources, from classical literature to sport and neurological science research.

Similar to Mouratoglou, Jofre believes that the stance and head position on serves and groundstrokes are related to eye, foot, and hand laterality, or dominance in the body. Here is a breakdown of Jofre's core beliefs concerning technique and eye dominance based on my personal correspondences with Porta:

There is a dominant eye that affects tennis technical development.
Eye dominance affects a player's personality and how they learn. Left eye dominant athletes are more creative, artistic and can be disorganized in their thought processes, according to Porta, while right-eyed athletes are more logical, organized, less emotional, and mathematically oriented. However a 2022 literature review found no studies investigating a link between eye dominance and psychological characteristics.
Jofre also states that peripheral vision is important in tennis and is reduced by watching screens and mobiles too much as many kids do today. He connects tactics with the vision field as well.
"Everything is tactics," he told me. "The decision we have to take in each situation is tactics. We must have better tools to better run tactics." Says Porta, "The vision of the game is directly proportional to the ability to perform a motor action while retaining an overview from the peripheral vision.

Paul Dorochenka taught eye dominance to Porta

Paul Dorochenko is a well-respected physiotherapist, osteopath, and physical trainer who worked on the professional tennis tour in the 1980s and has worked with many elite European athletes as a trainer and physiotherapist. He has trained many top professional players such as Roger Federer, Sergi Bruguera, Carlos Moya, and Sara Errani, among many others.

Dorochenko has been a strong proponent of the dominant eye theory as it relates to athletes and tennis players. Jofre Porta credits Dorochenko for teaching him about the dominant eye and its importance in tennis, and Mouratoglou's beliefs mirror many of the philosophies of Dorochenko. Dorochenko wrote a book, El Ojo Director, in 2013 in which he tells his experiences from the professional tennis tour and explains in detail his theories about the dominant eye, laterality, and athletes.

For Dorochenko, similar to Mouratoglou and Porta, the laterality of athletes has a profound impact on the way they play their sport and the techniques they use. He believes in creating a laterality profile for each athlete he trains based on eye, hand, hip, leg, and foot dominance. Dorochenko also argues that whether a player is homogeneous (same-side dominant) or crossed (crossed-dominant) is directly related to specific mental and emotional characteristics.

Whatever the eye dominance, the vast majority of high level backhands—both two hand and one hand--are hit closed stance.

But now let's see what high speed video says about one of the other major eye dominance claims about stances. In his video, Mouratoglou says that, on the backhand side, left eye dominant players should hit open stance to get the dominant eye closer to the ball.

Research shows that about 30% of all humans are left eye dominant, which we could assume that to be roughly the same for tennis players. So we could expect that somewhere around that same percentage of players would favor the open stance backhand.

But that is not the case when we look at backhands in the Tennisplayer Archives. If we look at 25 of the top men's players none of them hit predominantly open stance—it's a small percentage. There is a clear preference for closed stance, with players hitting on average 60 to 70 percent closed.

Neutral stance is second, used mostly around the center of the court. Open stance is a distant third, used primarily as an emergency stance when players are on the run. And there are even fewer open stance backhands with the one-handers.

If 30% or so of top players are left eye dominant it isn't reflected in stance choice. Closed stance is preferred because it increases hip and shoulder turn prior to the start of the forward swing.

Nadal and Federer take the ball at the front edge of the body, not between the legs.

But what about the claim that cross dominant players, allegedly Nadal and Federer have an advantage on the forehand? There is no evidence this diagnosis of cross dominance is even correct—it comes from coaches who claim to discern it from observation with the naked eye.

The eye dominant factions claim that cross dominant players can take the ball later, "between" the legs and that somehow this means they can keep the ball on the strings longer. Again that's not what the evidence shows.

Nadal and Federer have great turns, but not discernibly greater than the other top players. All top players turn more than 90 degrees to the net before the forward swing.

As for taking the ball "later" more between the legs, the video clearly shows they usually make contact at the edge of the front leg or even further in front. This is similar to other great forehands like those of Sinner and Alcaraz.

The duration of the contact is invisible to the naked eye.

And finally, as for keeping the ball on the strings "longer," it's not really possible and there is no way the human eye could discern it if was. The high speed evidence shows that this interval is virtually the same among top players—somewhere around 4 milliseconds, slightly less probably on the serve. That's about 10 times too fast for the human eye to resolve.

Eye dominance may sound like a compelling theory, particularly when marketed to players and parents who have a desire to learn "secrets" from "known" coaches. But the reality is something different.

My research shows there is a real danger that using flawed eye dominance testing and making unwarranted technical adjustments could harm a player's technical development. Stay tuned for my take on how the eyes should figure in Winning Pretty stroke development.

Is Eye Dominance Real in Tennis?

Chris Lewit