The old adage “You fight like you train and train how you fight” is the golden rule for combat effectiveness. Science has its own version of this, the SAID principle – an acronym that stands for Specific Adaptation to Imposed Demands. In other words, your body ALWAYS gets better at EXACTLY what it does (and how you do it).
In this series of articles, we are going to look at developing better marksmanship by training your nervous system and specifically your vision.
For tactical & military athletes, binocular vision or using both eyes together to see is paramount for both situational awareness, and accurately identifying and seeing targets. The US Army states in published research that the Sympathetic Nervous System, when activated by high-stress combat situations will force both eyes open. If you have proper functioning binocular vision and you “train like you fight” this should not pose a problem, however, it is estimated that as much as 56% of the general population has a defect in binocular vision. This means that one eye works significantly better than the other and the eyes do not work well enough together for the brain to combine both video streams into one.
For a tactical athlete who can’t produce stereo vision (vision using both eyes) their shooting accuracy may be be reduced with both eyes open compared to using only one eye to aim. To better understand what may prevent you from having good binocular vision, let’s start by defining what vision is and from there, we’ll define the core visual skills every tactical athlete needs to own.
Vision is Different from Eyesight
100% of vision occurs in the brain whereas eyesight pertains to the hardware (eyes). Because vision occurs in the brain, we can use neurological training to make our vision work better. Most people think of “eyesight” when they hear the word “vision”:
Eyesight is simply the ability to see something clearly, the so-called 20/20 eyesight (as measured in a standard eye examination with a Snellen chart). Vision goes beyond eyesight and can best be defined as the understanding of what is seen. Vision involves the ability to take incoming visual information, process that information and obtain meaning from it.”
– Dr. Donald Getz, OD
To help define what vision is, here is a list of Visual Skills as defined by Z-Health Performance Solutions:
The 9 Elements of Athletic Visual Skill
- Dynamic Visual Acuity – This is the visual skill that allows you to see objects clearly while the object is in motion. In virtually every sport this means that you need to have exceptionally good vision at distances ranging from a few inches to 300 feet. In a combat environment you need to have good vision at much further distances.
- Eye Tracking – Refers to your ability to “keep your eyes on the target,” no matter how fast it is traveling.
- Eye Focusing/Accommodation – The skill to change focus quickly and accurately from one distance to another.
- Peripheral Vision – Allows you to see people and objects “out of the corner of your eye” while concentrating on a fixed point.
- Vergence Flexibility and Stamina – The ability to keep both eyes working together in unison under high speed, physically stressful situations and differing environments.
- Depth Perception – This skill allows you to quickly and accurately judge the distance and speed of objects moving toward and away from you.
- Imagery – This skill allows you to picture events with your “mind’s eye” and your “virtual proprioception”.
- Sequencing – This refers to the ability to correctly see and “put in line” a series of stimuli. In other words, it refers to the ability to organize visual information which is a key skill to understanding and reacting to the events that occur in a sporting environment. Sequencing plays a role in virtually every sport.
- Eye-Hand & Eye-Foot Coordination – These crucial interactions are the ultimate basis of athletic skill. The ability to take in correct and appropriate visual information and translate it into necessary body movements is the essence of this skill set.
At a base level, every tactical athlete should be able to perform two foundational visual tasks that are necessary to be able to successfully do all 9 visual skills listed above:
- Gaze Stabilization (holding your gaze fixed and focused on a target)
- Create Binocular Vision (see with both eyes instead of just one)
Here’s a simple method for checking your gaze stabilization:
- Grab a business card and hold it out in front of you at arm’s length.
- Focus on the smallest detail of a letter that you can.
- Try and hold your gaze for at least 15 seconds.
- Repeat in a total of 8 positions (four cardinal directions, plus the 4 diagonal position in between them.
- If your eye moves at all or you find yourself losing focus or refocusing on the letter, then you are lacking in the gaze stabilization department.
Note: You should be able to hold your gaze steady and in-focus for at least 15-30 seconds in each position.
We will cover steps you can take to improve your gaze stabilization in Part 3.
In Part 2, we’ll take a look at how binocular vision is created and we’ll cover four easy screening tests you can use to test if you’re creating binocular vision and we’ll dive into the most common reasons athletes cannot achieve binocular vision and what to do about it.
Technical Contribution: Troy Dodson of Brain Based Fitness Rx
(Image courtesy of: commons.wikimedia.org)
Getz, D. J. (1973). Vision & Reading. Vision and Perception therapy Optometrist Network. Retrieved from http://children-special–needs. org/vision_therapy/esophoria_reading.html.
Goebel, J. A., Tungsiripat, N., Sinks, B., & Carmody, J. (2007). Gaze stabilization test: a new clinical test of unilateral vestibular dysfunction. Otology & neurotology, 28(1), 68-73.
Hussey, E. S. (2007). Correcting intermittent central suppression improves binocular marksmanship. Military medicine, 172(4), 414-417.
Maino, D. M. (2010). Editorials-The Binocular Vision Dysfunction Pandemic. Optometry and Vision Development, 41(1), 6. Retrieved from http://c.ymcdn.com/sites/www.covd.org/resource/resmgr/ovd41-1/editorial_binocularpandemic.pdf
Morrissey, M. C., Harman, E. A., & Johnson, M. J. (1995). Resistance training modes: specificity and effectiveness. Medicine and Science in Sports and Exercise, 27(5), 648-660.
Stone, M. H., Stone, M., Sands, W. A., & Sands, B. (2007). Principles and practice of resistance training. Human Kinetics.
The Eyes Have It: Vision and Movement Neurology. (n.d.). Retrieved from http://www.zhealth.net/articles/the-eyes-have-it