The development of prevention strategies is critical to address the rising prevalence of sport-related concussions. Visual and sensory performance may influence an individual's ability to interpret environmental cues, anticipate opponents' actions, and create appropriate motor responses limiting the severity of an impending head impact. The purpose of this study was to determine the relationship between traditional and visual sensory reaction time measures, and the association between visual and sensory performance and head impact severity in college football players. Thirty-eight collegiate football players participated in the study. We used real-time data collection instrumentation to record head impact biomechanics during games and practices. Our findings reveal no significant correlations between reaction time on traditional and visual sensory measures. We found a significant association between head impact severity and level of visual and sensory performance for multiple assessments, with low visual and sensory performers sustaining a higher number of severe head impacts. Our findings reveal a link between level of visual and sensory performance and head impact biomechanics. Future research will allow clinicians to have the most appropriate testing batteries to identify at-risk athletes and create interventions to decrease their risk of injurious head impacts.

The Effect of Visual and Sensory Performance on Head Impact Biomechanics in College Football Players

Purpose:To assess the effects of corneal collagen cross-linking (CXL) on contrast sensitivity (CS), visual acuity, and corneal topography investigating possible predictors of efficacy.Methods:Sixty-eight eyes of 34 patients with progressive keratoconus were enrolled in this prospective study. CXL wa

Effects of corneal cross-linking on contrast sensitivity, visual acuity, and corneal topography in patients with keratoconus.

CLEAR - Contact lens technologies of the future

Predicting optical effects of tear film break-up on retinal image quality using the shack-hartmann aberrometer and computational optical modeling.

Background The aim of this study was to investigate static and dynamic visual acuity, refractive error, and the use of visual compensation of elite football players. Methods From 2015 to 2017, 147 professional players from five teams were analysed. Screening consisted of a survey about the use of visual correction, and measurement refractive error, static visual acuity and dynamic visual acuity. Refractive error was assessed using an autorefractor. Distance static visual acuity was evaluated using a Snellen chart. Dynamic visual acuity was measured at five metres using the software COI-SV. All athletes were male with a mean age of 24.6 ± 4.1 years. Results The mean refractive error of the athletes was -0.04 ± 0.83 D, and 16.4 per cent were myopic. Statistically significant differences were found for dynamic visual acuity (p = 0.033), based on the position occupied. Goalkeepers displayed the best dynamic visual acuity and forwards had the lowest values (0.82 ± 0.14 and 0.62 ± 0.17, respectively). The forwards presented with the highest prevalence of myopia and goalkeepers the lowest, at 22.5 per cent and 12.5 per cent, respectively. All goalkeepers who needed to use a correction for play used it, whereas only 16 per cent of the forwards who needed a correction used it. Conclusion Dynamic visual acuity of forwards is lower than that of other players. Twenty-five per cent of players who need to use visual correction to practice sports actually use it.

Static and dynamic visual acuity and refractive errors in elite football players.

UNLABELLED : The building blocks of effective sports vision are visual acuity and contrast sensitivity. Proper measurement of these spatial vision attributes is necessary for repeatability in the clinic or in the laboratory. The most repeatable method of testing visual acuity is with logMAR charts-either the Bailey-Lovie chart or the Early Treatment Diabetic Retinopathy Study chart. The Pelli-Robson and the Mars are the most repeatable contrast sensitivity tests. Athletes may or may not demonstrate superior visual acuity and contrast sensitivity compared with age-matched nonathlete populations, and the optical quality of their eyes may be similar. Dynamic visual acuity in athletes and their performance are typically superior to those of nonathletes. How these differences relate to on-field performance is not known. Other changes to the visual system because of refractive surgery or contact lens wear may increase higher order aberrations and reduce low-contrast visual acuity. The ability to improve already-normal visual acuity is unclear although contrast sensitivity can improve with fast-paced video games. Tinted contact lenses help reduce discomfort glare and speed up adaptation but do not have an appreciable effect on visual acuity and contrast sensitivity. CONCLUSION The use of valid and repeatable visual acuity and contrast sensitivity tests is essential for measuring the differences in visual performance among athletes and nonathletes. The development of a standardized dynamic visual acuity test is needed as are well-controlled scientific studies to evaluate the benefits of sports vision training.

Kimberly L Lust

Papers

Visual acuity and contrast sensitivity testing for sports vision.