Dynamic vision crucial to first responder, military performance: OD Perspective
By Keith A. Smithson, OD
Keen eyesight and functional vision are both needed for first responders and military personnel to perform at the peak of their abilities. Eyesight takes place within the eye and refers to one’s ability to see clearly at all distances. Vision encompasses eyesight but goes beyond the idea of 20/20 and refers to one’s ability to understand what he or she sees. Unlike eyesight, which is static, vision is a dynamic process that takes place in the brain. Also, unlike eyesight, dynamic vision can be improved with practice and training. Optometrists are uniquely positioned to uncover and treat deficits in eye movement.
Dynamic Vision in the Real World
Unfortunately, some individuals may not realize they suffer from undiagnosed eye movement impairment that can reduce how effectively the eyes and brain work together. A standard eye examination checks for static visual acuity—eyesight—as well as the eye’s physical health, screening for retinal disease, glaucoma, or cataracts, but provides no information on how well the eyes function together. That is why the American Optometric Association recommends that eye care specialists evaluate patients for dynamic eye focusing, eye teaming, and eye movement along with visual acuity.1
In the case of first responders and military personnel, deficits in dynamic vision could be a matter of life or death. Identifying areas of visual deficiency with dynamic vision testing, and then assessing and treating those issues can have a dramatic effect on improving overall performance and safety. By going beyond vision screenings and employing technology like eye tracking, eye care specialists can not only evaluate dynamic vision but also help train front-line workers to see, process, react, and perform at a higher level. Ensuring those who serve and protect us can do all functions of their job at an elite standard is even more crucial than ever.
Visual Processing and Eye Movement
We know that 80% of all sensory information sent to the brain is received visually, which means that visual information and processing are crucial to everything we do, from learning to drive a car to playing sports.2 Once the brain receives information from an image, it tries to determine what it is, where it is, where the viewer’s body is in relation to the image, and how to react to it. Dynamic vision relies on experience in terms of what is known and what is expected to be seen. A person can have perfect eyesight and still not have optimal vision, which also requires both eyes to work in tandem, focusing alike.
There are 4 different types of eye movement that underpin the performance of vision-related skills at the highest level, whether it is on the battlefield or the playing field: saccades, smooth pursuits, vergence, and vestibulo-ocular reflex.3
Saccades are rapid eye movements that allow us to scan a scene quickly. Smooth pursuit visual behavior is when the eye tracks an object in linear fashion. Vergence allows the eyes to focus on different objects in three dimensions. Vestibulo-ocular movements compensate for movement, allowing us to see clearly by keeping our eyes on the intended visual target. To follow a target at high speed, one employs all four of these types of eye movements.4
Vision-related Skills for Performance
Dynamic vision plays a central role in job performance for first responders and military personnel. From assessing a scene to reacting to a threat to firing a weapon, the same vision skills on display during a soccer game are part of the toolset employed every day by professionals like soldiers and police. For an elite athlete, honing their visual skill set might mean a higher batting average or more touchdowns. When a law enforcement or military professional improves their quick decision-making ability, reaction speed, multiple object tracking, and threat assessment abilities, it can be the difference between life and death.
In my practice, a dynamic vision assessment takes about an hour. My team starts with a routine eye exam and eye health check, and then we employ technologies to obtain real-time data with objectively quantifiable numbers on dynamic vision skills. For example, I use noninvasive eye-tracking technology from RightEye which captures pictures of eye movements 30 to 250 times a second. This quantitative data allows eye care providers to identify issues in a measurable way and can also help monitor recovery and track improvement. Specific vision skills measured include dynamic visual focus, simple reaction time, binocular vision skills, smooth visual pursuit, choice reaction time, visual concentration, eye movement speed, discriminate reaction time, and contrast sensitivity. Using the graphical, easy-to-read report, I can review the patient’s overall profile and talk about areas that we can either remediate if there’s a concern or a problem, or areas we can work on to enhance vision.
I have had the privilege to work with a variety of military professionals and law enforcement organizations on visual training programs. These individuals are often in situations where they must make split-second decisions, under stress. Their safety and the safety of others depends on their abilities—and their dynamic vision. With so much at stake, we should ensure they have every advantage possible to perform their duties at the highest possible level.
Dr Smithson 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 a Vision Performance Consultant for Washington Capitals. He is the Co-Founder of Sports Vision Pros. He is the Co-Founder of Sports Vision Pros. Visit www.sportsvisionpros.com to learn more about enhancing visual performance.
1. See the full picture of your health with an annual comprehensive eye exam. American Optometric Association. Available at: https://www.aoa.org/healthy-eyes/caring-for-your-eyes/full-picture-of-eye-health?sso=y
2. How to keep your sight for life. Summer 2008 NIH MedlinePlus. Available at: https://magazine.medlineplus.gov/pdf/summer2008.pdf
3. Bahill T and LaRitz T. Why can’t batters keep their eye on the ball? American Scientist. May-June 1984. Available at: http://sysengr.engr.arizona.edu/publishedPapers/EyeOnBall.pdf
4. Fincham EF. The accommodation reflex and its stimulus. Br J Ophthalmol. 1951;35(7):381-393. doi:10.1136/bjo.35.7.381