Information contained within this article will give firearm
instructors and marksmanship students a better understanding of
how vision significantly contributes to shooting ability and
success. Appreciating the dominant role vision plays in
directing and monitoring most of the skills used during shooting
will prove useful in updating training methodology. The ultimate
result of incorporating useful scientific models and research
into a training curriculum should result in shooting performance
A comprehensive definition of vision goes beyond the classic
20/20 sight definition. A limited concept of vision is often
defined as the ability to see a sharp, clear, 20/20 or better
visual acuity image. However, defining vision as a dynamic,
learned process of deriving meaning and directing action from
light energy establishes a scientific model to better appreciate
the importance of vision for accurate and safe shooting.
Visual skills provide intelligent information to shooters
concerning where targets are located, what details and
characteristics constitute the target, as well as target speed
and direction of movement. This type of spatial, temporal and
labeling information is used to make a decision whether or not
to coordinate a response to shoot the target. Understanding how
visual abilities dominate the process of shooting targets
accurately and quickly will provide a framework to improve
An overview of the basic anatomy and physiology of how the
eye responds to light to begin the visual process establishes a
framework of reference. The amount and intensity of light
entering the eye dictates what neurological information is sent
via the optic nerve to the brain for processing and
interpretation. Generally, basic vision function is divided into
three levels of light intensity; daylight (photopic), twilight (mesopic)
and low light, night (scotopic) vision function.
Photopic vision functions during bright light levels.
Specific neuroreceptors called cones dominate the eye’s response
to bright levels of light. The inner photosensitive part of the
eye, called the retina, has approximately 7 million cones. Cones
are concentrated in the area of the retina that corresponds to
straight ahead vision. This anatomical area of the retina is
called the macula, and within the macula is a depression called
the fovea consisting almost entirely of cones. Cones convert
light energy into neural energy sending information via the
optic nerve to the brain. Reflected light from targets
stimulates cones to send information to the brain about forms,
shapes, textures, colors and high contrast sensitivity detection
of various line forms. This information is then combined and
analyzed by the brain to form an impression of the target.
From a practical perspective, only in daylight vision can
very precise detail and color of a target be seen. Also, precise
3-D depth perception (stereopsis) is only possible during
cone-dominated daylight viewing conditions. The highest degree
of depth perception occurs when the central, straight ahead
fixation point in each eye sends information to the brain in a
highly coordinated fashion. During low light conditions, the
cones are unable to send precise signals for the brain to
Daylight vision enables the eyes to maintain the highest
degree and control of eye fixation, the ability to maintain
steady and accurate eye position upon a stationary target. Also,
the ability to follow a moving target (called pursuit eye
movements) functions optimally during photopic viewing
conditions. A different type of eye movement of looking from one
separated target to another target to another target, etc.
(called saccadic eye movements) function much better during
bright light conditions than during low light conditions. The
voluntary act of allowing the extraocular muscles of the eye to
position the eye such that images fall on the retina where cone
density is highest is an important component of establishing
visual attention on targets.
The ability to maintain accurate focus (accommodation) on a
target requires sufficient light to activate the eye focusing
system. The accommodative response functions most efficiently
when the target reflects sufficient light to stimulate accurate
eye focus. Cones have the best ability to receive the refracted
light that the lens inside the eye alters during the act of
focusing clearly on a target. When light diminishes, the cone
function is suppressed and the quality of the eye focusing
Once bright light declines and darkness emerges, there is a
period of light transition (seen during dusk) defined as mesopia.
During mesopia there is a shift from cone domination of vision
to rod domination of vision. However, during mesopic vision,
both rods and cones are partially active. The 120 millions rods
are located throughout the entire peripheral retina. The main
functions of rods are to send visual information to the brain
about movement detection, organizing spatial orientation of
where targets may be located in space, and responding to low
levels of light that may be present in the environment. During
mesopia there is a gradual loss of color perception, gradual
loss of discerning target detail, gradual loss of the ability to
maintain accurate eye focus upon target, contrast sensitivity
losses, and a diminishing ability to maintain accurate three
dimensional depth perception. From a practical viewpoint,
mesopia is complete when color perception is eliminated, and at
this point, the visual system begins to function in scotopia.
When light levels fall into darkness, the human eye
functions in a state of scotopia. Rod physiology does not allow
for color vision nor the ability to discern detail. It is
estimated that the best visual acuity during scotopia is 20/200.
When you change from day vision to darkness immediately (e.g.
entering a dark room during the day), the dark adaptation of
cones is complete in five minutes, while full rod adaptation
takes about 30 minutes. However, rods are more sensitive than
cones at the seven-minute mark. Complete dark adaptation
requires about 30 minutes for the rods to reach their highest
level of sensitivity while in darkness.
The ability to maintain accurate eye focus upon a target is
greatly reduced during scotopic vision function. Other important
visual changes that accompany scotopic vision include increased
awareness of peripheral light and movement, increased pupil size
resulting in less depth of field, reduction in contrast
sensitivity, loss of texture perspective, altered target search
strategies and variability of eye focus control increases. It
follows that detection of the fine details of an object of
attention is greatly reduced. Unless there is added light source
directed at a target, the human visual system is unable to judge
accurately target characteristics such as size, shape, contour,
texture and color.
Above and beyond the basic visual functions that are
operational at various lighting conditions, there are specific
visual changes that occur when a shooter is threatened by a
dangerous situation. The Body Alarm Reaction (BAR) is the body’s
response to an unexpected and sudden change in the environment,
most commonly initiated during the early stages of a life
threatening attack. The BAR is often associated with combat or
violent encounters. The most immediate visual change in response
to the BAR is that the eye focusing system (accommodation) loses
it ability to maintain clear focus on targets at close
distances. It is not possible during the first few seconds after
entering into the BAR to clearly focus upon the front sights of
a gun. A shooter’s visual focusing and attention is drawn to
focus toward far distant viewing, toward infinity. This focusing
change toward far distant focus is a direct result of the change
from parasympathetic nervous system control to sympathetic
nervous system control. This shift in the autonomic nervous
system balance is responsible for changing how the crystalline
lens inside the eye changes it shape and optical power. During
the immediate stages of the BAR, the lens becomes less convex in
shape and this results in an optical shift of focus resulting in
clear focus only while viewing distant targets.
The autonomic nervous system has two major branches; the
parasympathetic and sympathetic branches. Generally speaking,
the sympathetic nervous system prepares the body for direct
action and confrontation by increasing heart pulse rate and
bringing blood supply to large muscle groups. Also, eye pupil
diameter increases, and the ciliary muscle relaxes, forcing a
shooter to focus the eyes at far distances, perhaps to be
behaviorally better prepared for a perceived oncoming threat.
There is a slight bulging of the eyes associated with
sympathetic nervous system dominance.
The parasympathetic nervous system allows you to maintain a
more relaxed, balanced state of readiness by slowing an
accelerated heart rate, decreasing pupil size, and allowing the
eye’s accommodative system to focus at increasingly close
distances of up to inches from your eyes. The parasympathetic
nervous system aims to bring neural physiology back to a state
of balance or relative homeostasis.
When the BAR is activated, along with the neural changes,
there are hormonal and other biochemical channels activated
concurrently by a part of the brain called the hypothalamus.
These chemical mediators are useful in helping maintain the
influence of the autonomic nervous system response by either
encouraging the body to stay in ‘high alert’ or by reversing
this high intensity response to strong stimuli and resume a more
normal relaxed controlled state of neural balance. However,
during the early stages of the BAR, adrenalin is released in the
body to further enhance the excitatory component of the BAR.
(see flow chart)
It is important to remember that the sympathetic nervous
system can exert its neural messengers either in a focal manner
(through secretion of noradrenalin or norepinephrine) at local
end organs (as is the case at the ciliary muscle of the eye’s
focusing system), or through releasing noradrenalin or
norepinephrine directly into the bloodstream to prepare the body
It is worthwhile to note that during the BAR there are a
series of other biochemical and hormonal changes that are
activated throughout the body. One example is that the adrenal
glands secrete a group of hormones called glucocorticoids.
Cortisol is the most prevalent of these hormones. Cortisol
increases blood sugar levels to contribute energy for muscle
function. Research has also correlated decreased learning and
decreased memory function, as well as attention anomalies with
increased cortisol levels in the body. These changes in response
to cortisol levels increasing during the BAR help explain, in
part, why visual memory and visual attention is narrowed during
the BAR. These types of physiological changes that accompany the
BAR begin to explain the perceptual changes called “tunnel
vision” and “perceptual narrowing”. Humans have an innate
tendency to narrow attention upon a threat during extreme
stress. It can be argued that learning how to expand peripheral
awareness of space can minimize the effects of “tunnel vision”
during the BAR. Other strategies to overcome the tunneling
effects of perceptual narrowing will be outlined in the visual
training section of this bulletin.
From a behavioral perspective, Dr. A. M. Skeffington, the
father of behavioral optometry, theorized that during stress,
the human ability to center on a task and identify and maintain
meaningful awareness on a specific target is severely hampered.
BAR type of stress causes a decline in your ability to derive
meaning from your visual memory image due to a perceptual
narrowing that accompanies the breakdown of optimal human
performance. His theory postulated in the 1940s has gained
strength and understanding during the last half century as much
current neurological and psychological research has proven the
bulk of his intuitive understanding of human responses to
Other behavioral and performance changes have been reported
to be associated with “perceptual narrowing”. The theory of
perceptual narrowing suggests that as the level of demand
increases on a central, straight ahead target, there will be a
corresponding decrease in the visual area surrounding the
central area from which peripheral information can be extracted.
Increased arousal causes increased narrowing of the attentional
focus, with a progressive elimination of input from the more
peripheral aspects of the visual field. Another way of viewing
“tunnel vision” is that as stress increases, there is a
reduction of cues used to regulate performance. When stress
levels are further increased, there is a further restriction in
the range of visual cues used to sample visual space. Under
stress, the useful field of view shrinks, and the amount of
processing of visual information is narrowed.
A summary of behavioral changes that are associated with high
levels of stress, such as seen during the BAR, include;
Narrowing of attention span and range of perceived
Reduction in problem-solving capabilities,
Oversight of long-term consequences,
Inefficiency in information search strategies,
Difficulties in maintaining attention to fine detail
With intense fear, there is also temporary loss of fine
visual-motor (e.g. eye-hand) coordination.
With the possibility of
some of the above mentioned changes affecting shooter’s during
high stress encounters, it follows that a person involved in a
combat situation may have difficulty accurately recording and
remembering all the details of an encounter. During the active
stages of the BAR, it may be quite difficult to recall with high
accuracy and detail the events that just occurred during a
shooting exchange. However, once the high stress has been
relieved and a shooter returns to a state of more controlled
relaxation, there may be recall of more visual images related to
a specific previous combat situation.
Contemporary visual research describes a parallel, dual
processing visual system that is useful to further understand
the complex nature of how visual information travels from the
retina to the brain. One pathway (M-pathway) is more sensitive
to coarse visual forms and images that move quickly. The other
pathway (P-pathway) is more sensitive to fine spatial details of
forms that are stationary or move at very slow rates.
It appears that the P-pathway processing visual information
that is dominated by central, detailed labeling of information,
whereas the M-pathway processes information dominated by
peripheral vision awareness of movement, orientation and
location of visual images. It may be that these pathways work in
a synchronous manner to efficiently process visual information.
Under high stress there seems to be an imbalance between the P
and M pathways such that one pathway overrides the other.
“Tunnel vision” appears to be related to P-pathway dominance and
M-pathway inhibition during the BAR.
There are certain visual attributes that relate to object
visibility that help shooters better understand why certain
targets are easier to see that other targets. For example, size
of a target is related to visibility because relatively larger
image sizes have the potential to stimulate more retinal cells
resulting in more information sent to the visual areas of the
brain for processing. This increases the chances of a more
accurate visual interpretation of the details of the target of
Contrast of a target is a critical variable directly related
to ease of visibility. Contrast corresponds to the ability to
discriminate a dark visual image from a lighter visual image
within a total visual surround. In general terms, contrast is
the relationship between the lighting intensity of two adjacent
areas. A dark target, approaching black (having no reflected
light) is most easily seen next to a white (reflecting all
light) background. Shades of gray that have similar light
reflective intensities are most difficult to visually
discriminate and separate because the contrast values are most
similar. Shading differences, reflective light patterns and
texture gradients are learned behaviors that improve a shooter’s
ability to recognize contrast.
Colors of objects have a direct influence on visibility in
daylight (photopic) conditions. In low light (scotopic)
conditions, color has no influence on visibility of a target
because rod cell physiology operates during scotopic conditions
and rod cells do not have color discrimination ability. The
colors white and yellow have the highest visibility potential,
followed by orange, red, green and blue. Since white reflects
all wavelengths of light visible to the human eye, white is
highly visible during daylight conditions.
Another visual attribute related to color and contrast is
brightness (luminance) of a target. When light falls upon a
target, it is absorbed or reflected. The light reflected by a
target is what the eye senses if the light is of sufficient
intensity to stimulate the cones and rods. Materials that
reflect or radiate the highest amount of light are most easily
seen by the human visual system. Brightness is a shooter’s
subjective appreciation of the intensity of light entering the
eye. However, glare, an excessive amount of light that serves no
purpose, can be counterproductive to ease of visibility.
Although movement of a target improves the ability to detect
a figure from its surroundings, at the same time, as speed of a
target increases, the ability to distinguish details of the
target decreases. It follows that once you fixate upon a target,
the chances of engaging and discerning details of the target
with precise eye-hand-mind coordination improves as the target
speed slows towards becoming stationary. Fixation control is the
ability to maintain steady and accurate eye position upon a
stationary target. Many visual factors influence improved
fixation control such as high contrast of target, color and size
of target, as well as flexible eye focusing skills. Fixation
control begins to deteriorate after a few seconds of steady
fixation because the eye has an innate tendency to continually
scan and move to change retinal areas of stimulation. Also, the
ability to follow a moving target (pursuit movements) uses other
neurological controls than do fixation control. Pursuit
movements, as well as fixation control, improve as the quality
of the target’s contrast and brightness increases.
The following visual skills are important for shooter speed and
accuracy of aim;
A. Visual acuity: Both static (discerning detail of a stationary
target) and dynamic visual acuity (discerning detail of a moving
target) is important to a marksman. Good dynamic acuity will
enhance a shooter’s visual reaction time and eye tracking
B. Peripheral vision: Skillful shooters have reported a visual
ability of maintaining an awareness of a central target while
simultaneously maintaining a vast amount of peripheral visual
awareness. A fully functioning visual system is capable of
responding to objects located within a total visual field (which
for each eye is approximately 40 degrees up, 60 degrees toward
the nose, 70 degrees down and 90 degrees towards the temple
measured from a central point of fixation). It is critical that
shooters are aware of what is beyond and around the target to
insure safety, and peripheral vision awareness is crucial to
achieve this task.
C. Depth perception: An essential skill for the shooter who
needs to judge relative distances between targets.
D. Eye motility: Eye tracking abilities are crucial to maintain
accurate detail and awareness of any moving target. This skill
is highly critical if a marksman needs to shoot a moving target.
E. Eye-hand-body-mind coordination: A necessary set of visual
coordinated abilities that are used in developing precise
trigger control while maintaining precise aim on target.
F. Visualization: The ability to use your “mind’s eye” to create
a mental visual picture when direct view of a target may not be
possible. This highly developed visual skill is useful to
anticipate where a target or adversary is most likely to be
located during episodes of lack of direct vision.
G. Speed of recognition time: Extremely important when a target
may be only visible for a brief moment in time. The ability to
accurately recognize as much of a target in as little as 0.01
seconds can be critical in deciding to shoot, or not shoot, a
H. Eye focusing flexibility: This ability plays an extremely
important part of a shooter’s ability to quickly adjust focus
upon targets that are located in different distances in space.
The speed and flexibility of quickly changing eye focus from one
point in space to another point in space has a direct influence
on maintaining clear, single binocular vision while in shooting
competition or in combat.
I. Color perception: May prove to be a useful skill when
confronted with the need to engage targets of specific coloring.
J. Fixation ability: Necessary to establish ‘sight picture’
awareness and consistency.
K. Visual memory: Used to embed the learning elements of
training to help skills reach the point of automaticity.
Training to the point of automaticity implies that the speed of
processing and performing a set of skills is fast, there is a
relative lack of effort to perform a skill, and the skill is
autonomous such that it may be initiated and run completely on
its own without an active voluntary conscious thought process.
The automaticity realization of shooting skills is useful in
avoiding visual perceptual overload resulting in confusion in
L. Central-peripheral awareness: The ability to have awareness
of central details of a target and simultaneously be aware of
the visual space surrounding the target (the peripheral space
around the target). This skill helps a shooter avoid getting
locked into “tunnel vision” for extended periods of time.
What is exciting to report
to shooters concerning the above mentioned visual skills is that
most all the skills (except for color vision) have a learned
component involved in the acquisition of the skill, and this
learned component can be trained to improve. Not only are there
testing procedures to determine how well these skills have
developed and how efficiently they function, but there is
emerging a growing body of visual training techniques which may
enhance performance in the visual skills important for shooting.
Sports visual training is the optometric art and science of fine
tuning and enhancing visual skills and abilities. Sports vision
practitioners are designing exercises and learning opportunities
to enhance and fine tune visual skills used during shooting.
Why are some shooters able to maintain visual-motor
(eye-hand) accuracy despite high arousal, as seen during the
BAR, leading to lower visual focusing control? There are various
models to help explain this paradoxically confusing relationship
of visually monitored marksmanship control during the BAR. The
one consistent thread that is part of most explanations is
professional, comprehensive firearms sports training, and
knowing when and how to implement this training with confidence.
Current neurobiological biofeedback research has clearly
demonstrated that humans can be trained to control certain
autonomic nervous system functions. This implies that with
proper training, particularly under stressful conditions, a well
established image of proper visual spatial alignment can be
maintained as a consistent eye-hand-body-mind coordinate system.
Shooters that can maintain sufficient and efficient
eye-hand-body-mind coordination control and adequate visual
attention during the BAR will be capable of accurate
marksmanship during high combat stress. It is becoming
increasingly evident that you can learn to “visualize” a visual
image even without having direct accommodation (direct focus) on
the object of regard. The ability to visualize and develop
improved eye-hand-body-mind coordination skills can be trained
using a variety of visual training techniques.
An example of a sports visual training exercise is ‘flash
recognition training’. This type of training is designed to
improve a shooter’s ability in the areas of speed of visual
recognition time and short term visual memory. The goal of this
technique is to accurately perceive and retain visual
information in increasingly shorter and shorter periods of time.
One behavioral outcome of this type of training may be increased
visual attention to increasingly complex visual stimuli.
During World War II optometrists used flash recognition
training to teach U.S. Navy Pilots airplane recognition. This
training reinforced optimal “visual posturing” (includes the
posture of every body part whose adjustment affects vision)
adjustments the pilots made to improve their visual perception
A 1995 research report discussed a three month visual
training program conducted with the Catalan Government Special
Intervention Squad at the Olympic Training Center in Spain.
Pre-test and post-test results were compared for pistol shooting
performance and visual function. Statistical analysis revealed
significant gains in visual function and pistol shooting scores
after the visual training program.
Another example of visual training is biofeedback training.
Using an instrument that allows you feedback as the relative
stimulation or relaxation of the eye focusing muscle (ciliary
muscle) can exert a carry over effect during intense shooting
competition. A learned behavior of voluntarily stimulating a
positive accommodation (parasympathetic response) during the BAR
can act as a counter force to the negative accommodation
response to the sympathetic nervous system stimulation during
Sports vision training has developed effective exercises to
enhance and fine- tune depth perception, eye motility and
movement speed and accuracy, eye-hand-body coordination,
visualization, speed and flexibility of eye focus and visual
memory skills. More information concerning visual training for
shooters, and practitioners that offer these services, is
available by contacting organizations listed below.
To learn more about sports vision training contact the following
organizations; www.covd.org, www.oep.org, www.aoanet.org
ABOUT THE AUTHOR: Edward C. Godnig, O.D., FCOVD, is a 1976
graduate of the New England College of Optometry, Boston,
Massachusetts. He maintains a private practice of optometry
specializing in behavioral optometry. Behavioral optometry is a
clinical discipline that diagnoses and treats visual skills and
abilities that have an impact on learning and movement
behaviors. Dr. Godnig has a particular interest in enhancing the
ability of shooters to use their visual system to improve
marksmanship. He has developed visual training exercises for
shooters to improve the skills necessary for fast and accurate
shooting. He can be reached at email address, firstname.lastname@example.org ,
for more information on visual training advice and seminars for
individuals or groups of marksmen.