I’ve started to do some sports vision work in my practice. There are lots of people in my locality who want to get better at their preferred sports and they are coming to me. I know what tests to perform but what do I do once I find a visual problem?
Remember, sports vision can be described as the science of helping athletes reach peak levels of performance through the enhancement of visual skills.
I outlined in a previous item that the following tests are useful when assessing sports vision:
- Monocular and binocular vision/visual measurement using a logMAR distance chart
- Monocular contrast sensitivity measurement
- Ocular tracking
- Ocular alignment
- Dynamic accommodation
- Dominant eye assessment
- Colour vision assessment
As I see it, there are two levels of treatment in sports vision. The treatment that is within the realm of standard optometric practice and treatment that involves the purchase of equipment which is often expensive and requires some practice in operation and understanding the results it produces. Here, I will concentrate on treatment which is in the realm of the standard optometric practice. I will leave treatment involving more sophisticated equipment to another item.
Optimum visual acuity is very important for life in general as well as for achieving optimum sports performance. Spectacles are sometimes appropriate for some sports, for example, tennis, badminton and squash where good fitting frames and polycarbonate lenses perhaps with a contrast-enhancing tint could be useful in achieving optimal performance and offering protection. However, for most sports frames may hinder peripheral vision and may risk trauma to the wearer and others if there is a collision. Contact lenses are the preferred choice for most sports. These are usually soft contact lenses as these are very much less likely to become dislodged from the eye than rigid gas permeable contact lenses. Full refractive correction of even small-0.25 DC-levels of astigmatism especially when oblique can be very useful.
Optimum contrast sensitivity is very important for achieving optimum sports performance. This can be achieved through tinted contact lenses, tinted spectacle lenses and tinted sports glasses without refractive correction.
Problems with ocular tracking need specialist equipment for accurate measurement and also for treatment.
Ocular alignment can be improved through the use of accurate refractive correction, convergence/divergence eye exercises, and through the use of prismatic correction-unfortunately, not available in contact lenses so this will be of limited use.
Dynamic accommodation can be improved through jump and push up eye exercises using large letters at distance and smaller ones at near.
The dominant eye is a fixed personal attribute once any refractive error has been corrected for. It is still useful to know for sports such as archery and also for advice on positioning on a field of play. For example, a footballer who is right dominant eye would be better positioned on the left side of the pitch so their dominant eye is on the same side of the football activity. Positioning a person with a right dominant eye of the right side of the pitch means they have the dominant eye towards the crowd of supporters.
Colour vision tests assess the ability to discriminate between different colours. Deficits in colour vision can make it difficult to identify team players where the opponents’ kit involves confusing colours and may make it difficult to see a ball against a similarly ‘confusing’ background, despite adequate static and dynamic acuity and good contrast sensitivity. It is not possible to treat colour vision anomalies but specially tinted contact lenses are reported to help with colour discrimination and could be used if necessary. Alternatively, awareness can allow for advice on possible compensations. Footballers often use sock colour to differentiate between teammate and opponent when they are looking down in tackles and short distance passes. Advice on making sure that the opponents have a sock colour which is within the range of colour discrimination of those with colour vision deficiency is one way to go.
Stereoacuity is derived from good and equal visual acuity, good ocular tracking and good ocular alignment. Any deficiency in one or more of these elements can be improved leading to improved depth perception.
Being able to provide even a 1% improvement in all these categories of these elements of visual function is very likely to lead to an improvement in sports performance through the aggregation of marginal gains.