Sports Vision includes:
• Basic optometric care
• Correction of any visual defects
• Glasses/Sports Eyewear
• Contact Lenses
• Refractive surgery including laser eye surgery
• Specific Vision Training
• Improving reaction time
• Improving speed of acquisition of 3D
• Improving visual perceptual skills
• Improving consistency of fixation
• Improving consistency and accuracy of eye movements
• Improving Eye-to-hand and eye-to-body accuracy
• Expanding peripheral awareness
Media
Irish Medical News 12th October 2009
Sports Vision: Maximising vision, maximising performance
Arthur Cummings FRCSEd (Consultant Ophthalmologist)
Clare Maguire (Sports Vision Optometrist)
(Wellington Eye Clinic and UPMC Beacon Hospital, Dublin)
When thinking about physical fitness, strength and overall sporting performance, the eyes do not automatically come to mind. You need sight to play sport; you cannot hit it, aim at it, know where it has come from, or where it should go, if you can’t see it.
Although athletes recognise that vision is an important aspect of their sport, many believe that they have perfect eyes. It is clear that there is a visual component to sport, but surprisingly, there is a general lack of awareness that this actually contributes to performance.
The eyes make up the major sensory input to the brain and in almost all sports, vision is the dominant sense. It has been suggested that 95% of all physical movement is controlled visually and that this is the trigger mechanism for the first movement of the athlete.1,2 Hence, choosing the most appropriate method and requirements of visual correction is essential in sport. People judge their vision by how clearly they see. However, vision is much more complex; there are many processes contributing to vision including speed and accuracy of focus, depth perception, peripheral awareness, stability of eye dominance and how efficiently the two eyes work together as a team.
Everything ophthalmology and optometry teach suggests that there is an inherent advantage in:
• Seeing with two eyes
• Having both eyes appropriately corrected and orthoptically balanced
• Being protected against trauma and non-ionising radiation
• Maximising contrast sensitivity
• Avoiding, recognising and treating pathology
If one could improve the vision and visual functioning, surely one’s sporting performance should improve. That is the basis of Sports Vision, a relatively new field that marries ophthalmology and optometry together like few areas in the two disciplines have before. Consider the following: with elite athletes, who have high visual demands, giving optimal visual correction (even as low as 0.25D) may just give them the edge. Of the five time-based Gold medals won by British athletes during the Athens 2004 Olympic Games, the cumulative time difference these athletes achieved collectively over the silver medal winners was just 0.545 seconds. Any advantage, though seemingly small, can make a big difference to performance at this level.
Our own experience in the field has yielded some remarkable results: we have treated footballers, hurlers, rugby players, soccer players and other team players. In individual pursuits such as with elite level golfers like Padraig Harrington and Paul McGinley, all have found that correcting the vision optimally has improved their sporting performance. This is as true for the young amateur school child as it is for the professional athlete. There are few sports where improved vision and visual performance is not an advantage.
Uncorrected visual problems can have a dramatic effect on sporting ability, not just in terms of focusing but also:
– balance
– timing and anticipation
– reaction times and aiming accuracy
– hand-eye-foot co-ordination
– glare recovery
– fatigue
– maintenance of high levels of concentration
Sports Vision by no means only includes visual acuity; it is a holistic understanding of the visual process, which goes far beyond the scope of a normal eye test. Most people will never have experienced such an in-depth eye examination as they do when having a Sports Vision assessment. The typical consultation lasts for about two hours, of which some time is spent with the ophthalmologist assessing the health of the eyes, the vision and visual quality. This includes corneal topography that maps the corneal contours with 24 000 reference points. Corneal tomography adds information on corneal thickness and the posterior surface of the cornea too. Finally, wavefront aberrometry maps, which measure the wavefront and any higher order errors that may be influencing visual quality, are performed if deemed necessary. If any errors are detected with these investigations, that decrease the visual quality, then a customised laser treatment is indicated. The ophthalmologist also manages the adverse effects on the eye that sport can have, with sport being one of the major causes of eye injuries. The majority of the assessment is spent with the Sports Vision optometrist and this includes basic optometry care and an in depth vision performance assessment.
Vision Performance Assessment
The laws of Sports Vision propose that the primary visual skills for sport are aiming and anticipation, and based on this a formal program of diagnostic and analytical tests has been developed. By anticipating a course of action, which way a tennis ball will be hit, response time is improved. Good anticipation skills can make up for the physiological limitations of reaction time and will be affected by visual skills which are amenable to investigation, correction and therapy. What marks the difference between the novice and the elite player, apart from physical development, is the ability to anticipate. Anticipation it would seem depends greatly on rapid interpretation of visual clues.
A full performance assessment will include a detailed history, concentrating particularly on any parts of the game that the athlete finds difficult or frustrating. This is followed by a number of tests that assess all aspects of vision. The results are discussed and advice given. Correction (contact lenses / sport specs / glare tints / laser vision correction) and vision training may be prescribed.
This information is combined with tests for binocular vision (how the eyes work together), fixation disparity (how well the two images are processed in the brain) and a measure of refraction.
A series of analytical tests may then be conducted to measure, for example, reaction time or hand / eye co-ordination, as appropriate for the athlete and / or sport. In some cases these may be carried out as team assessments to allow comparisons of individuals against the norm.
The diagnostic elements of visual performance evaluation are:
History:
As well as a detailed medical hist
ory, the athlete is asked if they recognise any of the following signs:
- Inconsistent performance
- Performance not up to potential
- Performance deteriorates over time
- Performance deteriorates under mental or physical stress
Eye Dominance (Fig.1)
Unstable eye dominance will affect balance and aiming. Its relationship to body dominance will have a dramatic effect on how well a player will perform. Certain eye-body dominances will give an advantage to many sports.
It had been thought that elite athletes would follow the rule of the general population being right handed and right eye dominant. Interestingly however, this was not the case. In archery, 80% of athletes are right dominant, but in cricket fewer than 50% of players screened were right dominant, the others being cross dominant (right or left contralateral).
This evidence suggests that dominance is an important aspect of vision in sport and may predispose people to particular sports.
Visual Acuity
Vision is measured at high and low contrast using logMAR charts. Low contrast vision gives a clearer indication of deficiency than high contrast and is a better representation of visual demand in real life, where contrast is reduced by mist, poor lighting or by distracting backgrounds (Hill 16).
Dynamic Visual Acuity
Clarity of a moving target. (Fig.2 – choose between 2 photographs included)
Refraction
This diagnoses myopia or hypermetropia, astigmatism or anisometropia. Even small amounts of myopia are likely to create difficulties and astigmatism causes a blur at distance and near.
Blurred vision in the dominant eye will affect aiming (kicking a point or catching a high ball) and in the non-dominant eye, anticipation or depth perception (timing the strike of a ball or catch).
Accommodative Function
How accurately you focus on what you are looking at, how well you maintain this focus and how quickly you can change your focus as the target moves.
Binocular Vision
How well the eyes work together as a team and how well they continue to work when the system is stressed. This has an effect on performance consistency, spatial location of the ball / target. Excessive divergence or convergence can be related to prescription and can affect anticipation or depth judgement.
Ocular Movement Skills
How accurately the eyes move. This includes pursuit tracking and convergence (eyes moving inward as a ball approaches). Inefficiencies will lead to mis-timing (early or late). ‘Keep your eye on the ball’.
Colour preference and Light sensitivity
Colour preference is affected by light sensitivity. For example, a liking for blue tints and a strong dislike for yellow is diagnostic of clinically significant light sensitivity.4 In outdoor sports inadequate protection for light sensitive eyes will measurably degrade visual performance.
Glare Sensitivity
Ability to cope with glare (low sun / stadium lights). Glare sensitivity is often caused by (correctable) problems with the focussing or binocular vision systems.
Depth Perception
3D judgement, spatial sensitivity. This is dramatically affected by binocular vision inefficiencies.
Visual Field and Peripheral Awareness.
The visual field around you and how you integrate information in it with your central vision.
Some interesting Sports Vision Facts:
• A study in the US found that 25% of athletes competing at a high level had never had a complete eye examination, although 29% had visual symptoms and 28% had less than 6/7.5 acuity with their habitual sports prescription and protective eyewear was not often used.5
• Several studies have compared visual performance among elite athletes with that of the general population and found significant differences. Researchers in the US measured the visual acuity, stereo acuity and contrast sensitivity of professional baseball players and found that they had significantly better visual skills. These athletes had an average visual acuity of 6/4+. On all tests of contrast sensitivity, and at all spatial frequencies, the baseball players had a greater sensitivity than the general population. Distance stereo-acuity was also superior.6
• Athletes often have a high visual demand and the literature has indicated that the optimal vision correction can enhance sporting performance even with corrections as small as –0.25DS. Correction over +1.00 hypermetropia is essential as this may relieve fatigue, especially for near and intermediate targets. Correcting small amounts of astigmatism (0.50D up) and anisometropia (0.50D or more) may also be beneficial.
– "No competitive athlete today can ignore the significant role that vision and visual skills have on their performance. You have to possess a superior visual system to be a superior athlete!" - Dr. Barry L. Seiller, Ophthalmologist (Founder Visual Fitness Institute®, Developer of Vizual Edge Performance Trainer)
Conclusion
It seems that vision in its basic sense can have a profound effect on sporting ability and sporting performance. A deficiency in visual performance will inhibit the development of sporting potential through poor eye / hand / body co-ordination, but perfect eyes do not make a perfect athlete. This depends on innate physiology (nature) and psychology (nurture).
1.Werner W. Contact lens fitting for sports. Contactologia 2000;22:92-4
2.Spinell MR. Contact lenses for athletes. Optom Clin 1993;3:57-76
3. Moorwood R and Griffiths GW. Visual performance in cricket. Optician 1998;215:5639 21-6.
4. Griffiths GW (2001) Colour preference: a comparative study. Optometry Today 41: 20.
5.Beckerman SA and Hitzerman S. The ocular and visual characteristics of an athletic population. Optometry 2001; 72:8 498-509
6. Laby DM, Rosenbaum AL, Kirschen DG et al. The visual function of professional baseball players. Am J Ophthalmol 1996;122:4 476-485
www.wellingtoneyeclinic.com
www.wellingtonsportsvision.com
Mr Arthur Cummings is Consultant Ophthalmologist at the Wellington Eye Clinic and the UPMC Beacon Hospital, and a former international swimmer.
Clare Maguire is a Clinical Optometrist at the Wellington Eye Clinic with a Diploma in Sports Vision Practice.
