Here’s the 4th article in Dr Skrdla’s YGR series.
Article One- Road Bike Visual Demands
Article Two- What is Dynamic Visual Acuity?
Article Three- Visual Information Processing
by Dr. Matthew Skrdla
Peripheral Vision is defined as the area of vision outside of our central 15 degrees of view. This is approximately a 2 ½ foot circular area when viewed at 10 feet. Peripheral Vision is physically limited by pupil size, where the eyes our located in the head (the front v. most animals where their eyes are more lateral) and the bridge of the nose. Our peripheral field is typically limited to about 160 degrees.
(The red dots indicate cones. The grey dots indicate rods. Rods are much more sensitive to motion and low light vision)
In relation to sport, and specifically cycling, it is more common to consider Peripheral Awareness. Peripheral Awareness is a trainable skill that can be improved!
At one point in our human evolution, Peripheral Awareness was a key to survival. Our peripheral field is much more sensitive to movement, especially under low light conditions. This was a critical skill for avoiding predators and other threats to survival.
Over the past several thousand years, there has been a rapid and dramatic shift to central focus and like any other skill if we don’t use it, we lose it. In relation to cycling, the less aware the athlete is of his/her peripheral environment, the greater the liability they are to themselves on the trail and to those in their group.
Cycling, and especially cycling in a group, is a unique sport for the ‘modern’ visual system and dormant peripheral awareness skill
set. To be a safe participant in a group ride, a cyclist must keep their visual attention independent from their focused vision (think ‘keep your head on a swivel’, without moving your head). For example, if you can (or are) reading the logo’s on the jersey in front of you, or a sign on the side of the road, realize your visual focus has just been reduced to 15 degrees (or less) and you have just become a liability to yourself and fellow cyclists as you will not be aware of potential ‘threats’. Without looking at individual logos, you can still be aware that it’s a black jersey, or an orange road sign/hazard cone while keeping your visual attention rapidly shifting from what’s in front of you to what’s around you.
Reactions to peripheral stimuli are significantly faster than those associated with central vision. Because of the physical and neural processing of peripheral stimuli, all points of peripheral field are simultaneously processed by our visual cortex. Simultaneous perception and what has been termed ‘Synchronoptical Ability’ is a critical skill for cyclists to develop for trail riding or group riding. This skill set essentially involves the ability to shift attention rapidly from our central field to our peripheral field while never ‘focusing’ on any one detail. Try allowing your vision to ‘de-focus’ on your monitor, right now, and you will immediately realize how much more aware you are of what’s around you. Now, bring your focus back to the letters and words and you will be aware of how much your field of awareness is reduced! Amazing!
Most cyclists have had an experience where they momentarily lose control, immediately reach for the brakes, and end up careening off the side of the road/trail as they are so intently focused on stopping that they can only see what’s directly in front of them (ex. Fabian Cancellara during the Olympic road race crashing over a barrier at a slow pace – watch his eyes: http://www.youtube.com/watch?v=0lwJydZswbY). Afterwards, we all know that if you can nurse or let off the brake, shift your focus up the road or trail for a safe route, and cruise through the corner that you come out like roses! This ability can be trained with practice!
To make sure you are not a liability on your next group ride or race, start here:
1) Maximize your field of vision (Peripheral Field of Vision) with protective eyewear/sunglasses that form to your face well, have large/wrap lenses for a wide field of view left/right/up/down, and a frame that does not obstruct your field of view (especially as you look over your shoulder to scan for other riders or cars)
2) Practice exercises that increase your ability to transfer attention to your peripheral field:
1a. Visit the following links and videos:
i. http://www.sportsvisionmagazine.com/training/vision/pv009.html
ii. http://www.sportsvisionmagazine.com/training/vision/pv019.html
iii. Try the following exercise:
