Keen dynamic vision can enhance first responders' performance
Static and dynamic visual acuity go hand in hand when it comes to successfully carrying out everyday activities. No matter the occupation, we need both good eyesight — visual acuity — and good vision — the ability to process what is seen — to get the job done effectively.
Seeing 20/20 on an eye chart is not enough. Life’s most essential activities require dynamic vision skills. Without dynamic vision skills, our balance, eye-hand coordination, reading comprehension, ability to drive and catch a ball, and our overall wellness is all compromised.
The totality of visual capabilities is especially critical for first responders, as it relates to their ability to carry out duties that require quickly scanning and assessing a situation and making appropriate, often split-second, decisions that at times mean the difference between life and death.
Because visual acuity is only a static measure of eyesight, it does not reflect critical components of dynamic vision like how well the eyes function together or one's ability to ascertain where a moving object is in space and in relation to the viewer. Dynamic vision involves eye tracking, focusing, eye teaming and visual processing, all of which can be objectively measured and even improved with training. There is a growing body of evidence that strengthening dynamic vision skills can enhance readiness, increase performance and decrease the risk of injury (Liu et al., Hunfalvay et al., Kiefer et al., Clark et al.).
Dynamic vision in the real world
Let's review the aspects of dynamic vision. Tracking is the ability to follow a moving object. Focusing means shifting between near and far in the visual field, while keeping both eyes clear and free of fatigue. Eye teaming is how well the eyes are working as one unit, maintaining a single image. Trouble with eye teaming can cause the brain to suppress information coming into one eye and potentially compromise depth perception. Finally, visual processing skills refer to the speed and efficiency of deciding how to respond to visual input. These abilities are all required to see while an object is in motion and while the viewer is in motion.
Honed visual processing skills can speed up the brain's ability to process information, improve decision-making, perform accurate threat assessments, and, therefore, allow the body to react properly and efficiently with the correct physical movement.
We know athletes for example, have better dynamic vision as shown by their reaction speed, and evidence shows these are trainable skills (Knudson et al., Liu et al.). In the case of first responders, any deficits in dynamic vision can have serious consequences for their safety and that of the public.
Recommendations for testing
The American Optometric Association has recommended that eye care specialists evaluate patients for dynamic eye focusing, eye teaming and eye movement along with visual acuity. There are a variety of tools and techniques at our disposal for testing dynamic vision and identifying areas of visual deficiency. Targeted training for improving dynamic vision might involve the following functions:
- Ocular-motor: Following a moving object, adjusting fixation from one object to the next;
- Vestibular: Consistently maintaining a stable gaze while in motion;
- Vergence: Adjusting focus and maintaining binocular vision when looking at different distances;
- Peripheral awareness: Seeing and responding to visual cues on the edge of the field of vision; and
- Contrast sensitivity: Determining incremental differences between light and dark shades in the same field of view.
I have been privileged to work with first responders on visual training programs as part of my practice in the Washington, D.C., area. Much is riding on these professionals having the ability to appropriately respond to visual information under stressful situations. Their safety and the safety of others depends on these skills; therefore, I believe it is part of our responsibility as eye care specialists to equip them with the testing and training they need to perform their duties at the highest possible level.
For an elite athlete, improving dynamic vision could net them a few extra points on their batting average, more touchdowns or a higher number of goals scored. For first responders, more lives could be saved if we can help them get better at quick decision-making, reaction speed, multiple object tracking or threat assessment.
- Liu S, Edmund FR, et al. Int J Perform Anal Sport. 2020; doi;10.1080/24748668.2020.1777819
- Hunfalvay M. OVP. 2018;6(1):9-10.
- Kiefer AW, et al. J Sci Med Sport. 2018;doi:10.1016/j.jsams.2017.06.016.
- Clark JF, et al. J Vis Exp. 2015;doi:10.3791/52648.
- Knudson D, et al. J Phys Ed Rec Dance. 2013;doi:10.1080/07303084.1997.10604922.
- Liu S, Ferris LM, et al. Psychol Sport Exerc. 2020; doi:10.1016/j.psychsport.2020.101759.
- American Optometric Association. See the full picture of your health with an annual comprehensive eye exam. Available at: https://www.aoa.org/healthy-eyes/caring-for-your-eyes/full-picture-of-eye-health?sso=y. Accessed November 19, 2020.
For more information:
Keith Smithson, OD, practices at Northern Virginia Doctors of Optometry. He is the director of visual performance for the Washington Nationals, the team optometrist for the Washington Wizards, Spirit, Mystics, D.C. United, and the Washington Football Team, and vision performance consultant for the Washington Capitals. Dr. Smithson can be reached at firstname.lastname@example.org.