Yesterday we looked at a new study that compared the pre- and post-training visual performance of athletes who used Nike’s new Vapor Strobes vs. a control group. The study aimed to test whether athletes’ visual performance increased after using the strobe goggles, which have lenses that flicker between clear and opaque to reduce the amount of visual information that the athlete receives, and found modest effects in some areas, none in others.
It makes for a nice jumping-off point to talk about the field of “sports vision training”, “eye training” or “sensory training” and the hardware vs. software debate around which skills in the visual-perceptual-cognitive system are most apt to improve through training.
The “hardware” aspect refers to the more specifically visual piece of the visual-cognitive system–so things like the shape of a person’s eyeball, the sensitivity of his/her rods and cones in the retina, and the conduction speed of the optic nerve–for example. The “software” aspect refers to what the brain actually does with this raw input–how we perceive the information that our eyes feed us, what that perception means to us, and ultimately, how we act on that information.
“Sports vision training” as the name might imply, tends to focus on the hardware side of the equation. Tests of sports vision ability involve measuring visual acuity (e.g. how well you see, as measured by an eye chart), vergence and accomodation (how quickly you can change focus from something nearby to something far away), contrast sensitivity, and other visual skills The idea being that raw visual skills are important to athletic performance, and that training these skills will lead to gains that show up on the field.
The research is a little murky around the efficacy of sports vision training. First, it is debatable whether elite athletes have superior visual skills–hardware–compared to the general populace. Some studies have found differences in some visual skills (here, here, here), others cast doubt on that proposition (here, here, here). However, in decades of research there has yet to be a slam-dunk study showing that athletes visual systems truly are superior, or that training an already-functional visual system makes an athlete any better off. Literature reviews over the years have produced perspectives ranging from intrigue and hope:
“These efforts, though incomplete, have suggested that certain visual skills are important to performance in selected sports and that the visual skills of athletes and nonathletes do differ. There is as yet a paucity of research to support the hypothesis that the visual skills of athletes can be enhanced by visual training and that enhanced visual skills will result in improved athletic performance. Additional research efforts are needed to answer the many intriguing questions posed by the relationship between vision and sports.”
To findings that have said that sports vision training is basically hogwash:
“Contrary to the claims made by proponents of generalized visual training, we found no evidence that the visual training programmes led to improvements in either vision or motor performance above and beyond those resulting simply from test familiarity.”
The other side of the debate aims to approach testing and training via the perceptual-cognitive route–how the brain controls the eyes and what it does with the information they provide. For example, while the research around whether athletes have better vision is questionable, research on the gaze patterns of elite athletes can very solidly say that highly-trained athletes use different visual search strategies than non-experts. It isn’t what or how well they can see, it’s what they are paying attention to, which is an important distinction. And multiple studies in multiple sports have shown that tests focusing on higher-order, cognitive skills are in fact effective in differentiating high-level athletes from novices (Soccer, Baseball, Basketball, Tennis).
However, the questions around cognitive training are not cut-and-dry. One of the seductive things about sports vision training is that it’s easy to create and design training–you train your eyes and, supposedly, performance improvements follow–something that research has yet to support. Even when gains in visual skills have been demonstrated, studies have been unable to answer the question of whether the athletes truly acquired generalizable skills, or whether they merely became more familiar with the test. Similar questions emerge around cognitive training. The holy grail is to create training that trains “transferable” skills–the ones that you can carry around with you from practice into the game.
So while the research is fairly clear that it’s really the software in an athlete’s head that sets him or her apart, the path toward true, research-supported training is still being cleared.