The purpose of sports vision evaluation is to optimize the athletes’ vision for sports performance. Contrast sensitivity is the best measure to evaluate visual performance of an athlete. It can be used in many aspects of sports vision evaluation.
Contrast sensitivity can determine which type of correction is best for visual performance.
Sports Vision and Contact Lenses
Many athletes prefer to wear contact lenses, as opposed to spectacles, during competitive activities. Contrast sensitivity can be used to determine which contact lens provides the best vision for an athlete. The evaluation is particularly important when the athlete has residual astigmatism, which may dramatically affect vision through soft contact lenses. Contrast sensitivity can be used to determine whether a toric lens or the spherical equivalent is better for the athlete.
“I’ve used the CSV-1000 with my client-athletes for many years, beginning with the 1992 Olympic Games in France and Spain. It’s rapid, accurate measurement of CSF is a critical part of my visual performance vision evaluation. Indeed, based on the CSV-1000’s results, I’ve optimized the fit and performance of more contact lens clients than I can count. The CSV-1000 is a must have instrument for sports vision evaluation.”
Dr. Fred Edmunds
XTREMESIGHT Performance Clinic
Contrast sensitivity can be used to measure the visual performance impact of residual astigmatism in an athlete when acuity shows little effect.
The contrast sensitivity of athletes can be particularly important in low contrast situations or when the athlete has difficulty discriminating objects from the background. For example, a downhill skier may have difficulty discriminating a mogul against the background of icy snow. Elevated contrast sensitivity of this athlete can help to improve the downhill times by avoiding moguls or indentations he/she would otherwise not see. The contrast sensitivity testing has also been shown to be useful in helping skiers to determine which goggles provide the best visibility (ie best contrast sensitivity) under low contrast, the so called “flat light” conditions. Another example would be helping athletes playing tennis or baseball under the lights, where the ball does not present a high contrast against the background. With elevated contrast sensitivity, the athlete can get a better “jump” on the tennis ball as it leaves the tennis racket of the opponent or of the baseball as it leaves the bat of a hitter or departs the hand of a pitcher.
Sunglasses and Contrast Sensitivity
Participation in outdoor sporting activities, such as tennis or softball, many times requires the athlete to wear sunglasses. Contrast sensitivity can be used to determine which type of sunglass tint and optics provides the best functional vision. In the examination, evaluate the patient with best correction without the sunglasses and then with best correction with the sunglasses. A loss in contrast sensitivity of 2 contrast levels (.3 log units) indicates that the sunglasses may impede the athlete’s visual performance.
Glare Sensitivity and Sunglasses
Contrast sensitivity tested with glare can be used to determine how effectively a certain type of sunglasses prevents vision loss in glare conditions.
Sunglasses should also be evaluated to determine how well the sunglasses preserve visual function during glare conditions. Using the VectorVision CSV-1000 Halogen Glare Test, the patient should be evaluated with each pair of sunglasses to determine how much glare is required for the athlete to lose two contrast levels of contrast sensitivity for each pair.
The athlete and doctor can combine the results from the contrast sensitivity test and the glare test to determine which type of sunglasses provides for the most protection from high glare conditions (i.e. looking into the sun to hit a tennis ball or catch a softball), while not impeding visual function during standard glare conditions (performing in bright conditions, but not looking into the sun).
Multifocal Contact Lenses and Sports
Contrast sensitivity can be used to determine if a multifocal contact lens affects the patient’s functional vision. Here the lens reduces the contrast sensitivity outside the normal range.
Many “Baby-Boomers” are now in the presbyopic age group and want the convenience of the multifocal or bifocal contact lenses. In some patients, these lenses may impact the visual performance needed in competitive situations. Contrast sensitivity testing can determine whether any loss in distance contrast sensitivity occurs with the multifocal lens. This information can be used by the patient to determine if perhaps, spectacles or single-vision lenses, should be used during athletic endeavors.