by Alex Andrich, OD, FCOVD
During periods of stress, the sympathetic nervous system automatically narrows the range of perceptual inputs to emphasize central vision.
This perceptual narrowing is an evolutionary skill that was quite useful for the survival of ancient humans, allowing them to tune out the monkeys in the trees in order to focus on the lion preparing to eat them. It is much less useful on the soccer field, where failure to notice the ball or an attacking player coming from the side can increase the risk of injury.
Female soccer players sustain more concussions than male or female athletes in any other high school sport, including football (Schallmo et al.) Research conducted at the University of Cincinnati suggests this may be due in part to perceptual narrowing and another automatic response to perceived risk, the startle reflex. The UC researchers found that female high school soccer players close their eyes when heading the ball 91% of the time, versus 79% of the time for males (Clark et al.).
The good news is that training soccer players to suppress the startle reflex and improve awareness of peripheral vision can reduce their chance of concussion. With good awareness of the periphery, for example, the player can drive the ball towards the goal, but at the same time avoid or brace himself or herself for a collision.
Concussion avoidance is getting a lot of attention in youth and professional sports. We know now that concussions can have long-lasting effects, especially if a player sustains a second hit while concussed. If the first hit is ignored (or goes undetected) and the athlete continues playing, their coordination, reaction time and peripheral awareness may all be greatly reduced, putting them at high risk for a dangerous second concussion.
In addition to preventing injury, training athletes on peripheral vision can also improve performance. Elite athletes often have naturally superior peripheral visual awareness. Think of the ability of NFL quarterbacks, for example, to find an open receiver anywhere on the field. And just watch this video for a great example of how John Wall, a top-level NBA basketball player, can channel his attention to the periphery with great accuracy, even while looking straight ahead.
The implications of training to overcome perceptual narrowing go well beyond sports. Military and police officers also routinely experience tunnel vision during stressful situations, which can blind them to important information and put their lives (and those of innocent bystanders) in danger. To a lesser extent, we all experience this phenomenon in daily life. Ever been in a rush to leave the house and can’t find your keys, only to eventually discover they were sitting on the kitchen counter the entire time? The relatively minor stress of being in a hurry has likely reduced your peripheral awareness.
Neuro-optometric and sports vision specialists use specific tools to improve central-peripheral integration, the skill needed to keep the brain from blocking out peripheral visual inputs. A light board saccadic fixation device or a FitLight Trainer require the user to look at a central fixation point while hitting or swiping peripheral targets with their hands as they light up. With more conscious efforts to integrate these tools into routine training for young athletes, we can help them stay safe — and maybe get just a little closer to that John Wall skill level at the same time.
Clark JF, et al. Med Hypotheses. 2017;doi:10.1016/j.mehy.2016.12.016.
Schallmo MS, et al. J Bone Joint Surg Am. 2017;doi:10.2106/JBJS.16.01573.
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Alex Andrich, OD, FCOVD, is in practice at the Vision Development Team in North Royalton, Ohio. He is also president of the International Sports Vision Association.
Disclosure: Andrich reports no relevant financial disclosures.
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