JOIN OUR MAILING LIST
Sports vision is the study of the role of vision in the dynamic sporting environment, the assessment of an athletes visual skills and the application of techniques, procedures or products that will correct, protect and enhance an athletes visual abilities and in so doing their sporting performance.
There are certain visual skills that are more important in some sports, and less so in others. For example, visual reaction time is far more important to an opening batsman in cricket who has to face an oncoming ball at 100kph than it is to an archer who takes time to align their shot.
Thus the sports vision practitioner needs to work with athletes and coaches to understand the skills required in their particular sport and concentrate on the enhancement of those skill as opposed to a generic list of less important skills.
The foundation of good dynamic visual acuity is good static visual acuity but because of the involvement of the ocular-motor system in dynamic visual acuity the efficiency of dynamic visual acuity (DVA) is determined by the efficiency of the ocular movements.
Contrast sensitivity is the ability to detect border contrast. As the brightness and colour of the background areas approach that of the object the athlete is following, seeing the following object becomes more difficult. Typical examples would be when the athlete fails to "pick up" a ball or loose tract of a ball against the crowd (the background). In sports such as cricket they introduced side screens to increase the contrast to help the batsman to see the ball. The importance of this test will be determined by the sports specific needs.
Under bright light conditions the human visual system has a highly developed sense to discriminate millions of different colours. Colour vision is a function of the cones in the retina and therefore our ability to perceive colours is drastically reduced un night conditions. The ability to discriminate a colour from its background will be greatly influenced by the respective colours. Cricket is a good example where a red ball is used for daytime matches and a white ball for night games. The other aspect of colour discrimination is congenital or acquired colour defective vision. Deficits in colour discrimination will effect the ability of the athlete to appreciated proper contrast sensitivity and therefore also seeing and tracking objects. It may also be difficult to tell one's team members from that of one's competitors. Depending on the sports it may be a serious obstacle for example in rugby and basketball where quick passing is needed or in snooker where a player may mistake a red ball for a brown ball.
Eye Movements (Ocular motilities)
This is the ability of the athlete to accurately use their two eyes together to fixate on an object or target and maintain this fixation while the athlete and/or object is in motion or stationary. This may require a smooth tracking movement or quick jump movements as the athlete quickly looks from one object to another. Deficits in this ability can affect all judgements of spatial orientation, relationships, depth perception and the need for immediate clear, single vision for all objects of regard in the field of view. The ocular-motor system is composed of two eye-movement systems. First the smooth pursuit system which is capable of matching eye-movement speed with the speed of the moving object to maintain a stable retinal image. The second system is the saccadic eye movement system which detects and corrects differences between object location and eye fixation.
Depth Perception (Stereopsis)
Although the terms depth perception and stereopsis are used synonymously, they are identical. An athlete with only one functional eye can achieve depth perception but stereopsis requires binocular vision. Stereoscopic vision is the ability to judge the relative distances of objects from the athlete by means of binocular vision only. It is because this ability to perceive space three-dimensional depends solely on the small disparities between the retinal images in the two eyes, i.e. each eye sees the same object from a slightly different angle. Stereopsis is the most highly refined attainment of binocular vision and is of the utmost importance in any sports where the relative distance of moving or stationary objects need to be judged with great precision. This is true for many sports such as cricket, squash, cycling and many more.
Focus Flexibility (Accommodation)
This test reflects the athlete's ability to rapidly change focus from one point in space to another allowing the athlete to maintain a clear focus image of the ball, person, etc. The mechanism for focussing as different distances is supplied by the crystalline lens of the eye and is called accommodation. This normal eye is relaxed when viewing objects at distance. For objects closer to the athlete, accommodation comes into apply. The demand for accommodation is at its highest at the plane of the eyes. In several sports it is important to track an approaching ball or object by quickly focussing as it moves towards them and also the relax accommodation as it travels away.
Fusion Flexibility (Binocular Stability)
This is the ability of the athlete to rapidly and accurately fuse the two images from their eyes into one image and to let the eyes work together with eye-movements, depth perception and focus flexibility to achieve this. Therefore deficits in fusion flexibility can cause an athlete to experience double vision, miss-judge directions and distances during competition and have difficulty in following objects and people in the field of view. The result is an overall poorer performance from the athlete. Because of the influence of other factors on fusion flexibility the athlete's performance is quite often erratic rather than just poor.
This is the ability of the athlete to maintain central fixation on a target yet to be aware of what is happening to the sides or in the peripheral visual field. Central-peripheral awareness is a function of visual perception and evaluates the athlete's ability to respond to central and peripheral without moving their head. Several sports require high degrees of central-peripheral awareness. Typical situations are where athletes must concentrate on a ball (central fixation) while also being aware of the position of team mates, opponents and boundary lines.
This skill involves the integration of the eyes and the hands. It determines the effectiveness of a perceptual motor response to a visual stimulus. There is no doubt eye-hand coordination is an important skill in many sports. The nature of this skill will invariably require a multi-disciplinary approach. Eye-hand coordination is most often regarded as a measure of an athlete's ability to institute a quick and accurate response to a stimulus. It may, however, also be pro-active, i.e. initiated by the athlete themselves such as bowling in cricket. The reactive type refers to the response by the athlete, like the batsman hitting the ball.
This test measures the efficiency of an athlete to adjust their balance in response to visual stimulus. It requires an integration of the senses of vision, equilibrium and proprioception, which are the three most important sense in the performance of the motor skills. This skill is important to all sports such as rugby, gymnastics, soccer, hockey, basketball, etc, where rapid and efficient shifting of balance in the legs and feet is required.
Visual Reaction Time
This is the time required to perceive and respond to visual stimulation. In essence it is very similar to eye-hand coordination but it actually combines the pro-action and the reaction parts. It is extremely useful in sports such as boxing where it can provide an accurate measure of hand speed.
This skill presents the flexibility in the athlete's visual system to allow them to rapidly adjust and guide the body's motor responses quickly and accurately while having changes in the surroundings or environment. It is the art of being tuned to body responses even though the demands may vary. The time it takes the visual system to adjust to these changes in demands will eventually determine the efficiency of the motor response.
This is the ability to pay constant active attention to visual stimuli. In certain situations such as race car driving this skill may be needed for long periods of time without any rest periods in between while in other sports such as cricket the batsman can have regular breaks in between deliveries. This ability is also regarded as a measure of how little visual information is required for the athlete to respond to a stimulus.
Visualisation (Imagery / Visual Memory)
This is the ability to mentally imagine and rehearse situations, actions and responses that can and do occur during sporting activities. The athlete can also mentally modify them to be more efficient and correct and then be able to use this information in actual play situations now and in the future.
|Back||Back to top|