RELEVANT MEDICAL RESEARCH
The following excerpts from accredited medical vision research are pertinent to functions inherent to the HexSite®.
Relevancy of research to HexSite® is indicated in paragraphs entitled “(HexSite® Note)”
VISION AND SHOOTING By Edward C. Godnig, OD, FCOVD
Staff Member, Police Policy Studies Council
http://www.theppsc.org/Staff/Godnig/vision_and_shooting.htm
….. “Understanding how visual abilities dominate the process of shooting targets accurately and quickly will provide a framework to improve firearms instruction.”
….. “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 often is associated with combat or violent encounters. The most immediate visual change in response to the BAR is that the eye focusing system (accommodation) loses its 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. ….. 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.”
(HexSite® Note): Adversarial startled-response focus is neveron gun sights. Focus is on the more distant target -- the threat -- and it is physically impossible for the human eye to focus on more than one focal plane at the same time. The HexSite® is specifically designed for combat situations because the shooter does not look at it. He looks through it at the threat. Then, unlike a circular ghost ring sight, the HexSite® does its job -- the hexagon’s 16 implied-line angles involuntarily, without conscious effort, draw his focus through its precise center onto the threat. The HexSite® functions for an embattled shooter because it is designed
It is a combat sight. |
….. “Reflected light from targets stimulates cones (of the eye structure) 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 ….. to form an impression of the target. ….. 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 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 the visual system begins to function in scotopia ….. visual changes ….. include increased awareness of peripheral light and movement, increased pupil size resulting in less depth of field, reduction in contrast sensitivity…..”
….. “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.” ….. “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.” ….. “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.”
….. “Reflected light from targets stimulates cones (of the eye structure) 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 ….. to form an impression of the target. ….. Once bright light declines and darkness emerges, there is a period of light transition (seen during dusk) defined as mesopia.” ….. “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.” ….. “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.” ….. “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.” As to various sometimes-effective Holographic Weapon Sights (HWS), their main liability is that they are not self-regulating in an ambient light environment. They need perpetually to be adjusted -- either turned up to maximum intensity in order to afford contrast ina high-intensity lighting environment, or, turned down to extremely low-level in low light, Conversely, the HexSite® does not induce any synthetic light source into the natural light environment. Therefore, it is self-regulating, as manifested by the lowest-value attributes of its rear-concavity contrast design. It requires no operator adjustment because it is harmonious with the existing ambient light environment. The concavity takes it to “dark”’ and not to “light” – light distracts the eye. The target must be the highest (lightest) value for successful sighting. |
….. “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.”
….. “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.”
….. “Visual memory: Used to embed the learning elements of training to help skills reach the point of automaticity ….. 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 target recognition.”
(HexSite® Note): Use of the HexSite® negates the impact of fixation control. With this combat sight, the shooter experiences quick target acquisition, so there is no need for the “marksmanship tradition” of fixation control (the prolonged aim of a target-shooter). Anyway, fixation control “begins to deteriorate after a few seconds” (see above). As to “pursuit movement” on a moving target, the unobstructive design of HexSite®, together with its intended use with both eyes open (natural binocular vision), improves “pursuit movement” because the quality of the target’s contrast and brightness is enhanced by the HexSite®’s rear concavity. |
….. “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.”
(HexSite® Note): The “openness” of this sighting system provides maximum target area and peripheral vision to the shooter’s vision, averting such surprises as unintended targets and the |
****************************
THE ANATOMY OF FEAR AND HOW IT RELATES TO
SURVIVAL SKILLS TRAINING
By Darren Laur (Copyrighted 2002)
Integrated street Combatives
http://www.lwcbooks.com/articles/anatomy.html
….. “During this 1992 research project, I had the opportunity to read an article authored by Bruce Siddle and Dr. Hal Breedlove entitled, “Survival Stress Reaction”. In this article, Siddle and Breedlove stated:
….. “‘Research by numerous studies provide two clear messages why people will place themselves in bad tactical situations. The common phenomena of backing away under survival stress results from the visual system’s deterioration of the peripheral field to attain more information regarding threat stimulus. Since the brain is demanding more information to deal with the threat, the officer will invariably retreat from the threat to widen the peripheral field. Secondly, the brain’s normal ability to process (analyze and evaluate) a wide range of information quickly is focused to specific items. Therefore, additional cues, which would normally be processed, are lost. This explains why people cannot remember seeing or identifying specific facts which were relatively close to the threat.’”
(HexSite® Note): We are in basic agreement with the above findings. However, in our experimentation and testing, certain characteristics of the HexSite®, together with recommended training techniques in using this combat sight, mitigate these findings.
|
….. “Increased Heart Rate:”
….. “We know that Survival Stress Reaction (SSR) is directly related to an increased heart rate”. …. ”At approximately 175 bpm (beats per minute), a person will experience an eye/lid lift, pupils will dilate and flatten. ….. visual narrowing (…..tunnel vision). This is why it is very common for a person to back up from a threat in order to get more information through this tunnel. It is also at this point in time that a person becomes ‘binocular’ rather than ‘monocular’. This is why in Close Quarter Battle (CQB) shooting, I teach two-eye ‘binocular’ shooting rather than one-eye aimed shooting.”
| (HexSite® Note): AMEN !!! |
….. “At 175 bpm, visual tracking becomes difficult. This is very important when it comes to multiple threats. During multiples, the brain will want the visual system to stay with what it sees to be the primary threat. Once this threat has been neutralized, the brain and visual system will then find its next threat. This is commonly known as the “lighthouse” effect. Studies have found that a person in SSR will experience on average about a 70% decrease in their visual field. This is one reason why, in combat, we need to teach students to constantly be scanning their environment, looking for the second and third opponent.”
….. “At 175 bpm, it also becomes difficult to focus on a close object. One of the first things to go under SSR is depth perception. A fighter WILL become far-sighted rather than near-sighted.” ….. “Studies in SSR have shown that binocular fighting/shooting will improve one’s depth perception by 20-30%.”
(HexSite Note): Because standard sights become obstructive, when addressing multiple threats, the shooter often will overswing his target and either miss his shot or lose time in reversing his swing to acquire the target. The HexSite® is advantageous because of its openness – the shooter looks through it at the primary target (threat) and, when moving to multiple targets, is less likely to overswing because the threats are never lost sight of. |
….. “In a study conducted by Dr. Alexis Artwohl (author of ‘Deadly Force Encounters’) between the years of 1994-1999, she interviewed 157 police officers involved in deadly-force shootings.
Dr. Artwohl’s study revealed the following results:
“79% experienced tunnel vision (peripheral narrowing)”.
“74% experienced ‘automatic pilot’ with little or no conscious thought.”
(HexSite® Note):
|
“26% experienced intrusive distracting thoughts.”
| (HexSite® Note): Such as, perhaps, “Why can’t I focus on my damned sights??” |
….. “As I said earlier, SSR is an autonomic response, which happens without conscious thought. Having said this, Siddle, in his research, has found that a person can manage SSR to attain that peak 115-145 bpm range in the following ways:
“Skill Confidence: This takes place through both mental and physical training.”
“Experience Through Dynamic Simulation Training:
Experience increases and builds confidence – reduces “newness” of stimulus;
Training should be ‘realistic’ stimulus/response based;
The more real the training experience (stimulus) the better.”
(HexSite® Note): Absolutely correct! We suggest you re-read Item 2 of the first ( HexSite® Note) of the Laur research paper, above, relative to shooter mindset in addressing a life-threatening threat “with prejudice”, and the form and techniques necessary to accomplish that life-saving task. |
….. “Value of Life:
- “In our society, a person’s life is considered to be precious. In fact, most of our morals and laws are based upon protecting oneself and others against serious injury or death.
- “In a self-defense situation, one may have to seriously injure or even kill another human being.
- “Although a reality, many people involved in combative training have not ‘really’ internalized or even thought about this. Because of one’s ‘belief system’, to kill or seriously injure another person is as foreign to them as committing suicide.
- “If one does not come to grips with this issue, one will fail to act in such a situation.”
(HexSite® Note): Well said! Obviously part of the concept of “prejudiced mindset”. In another context, related to value of life, is the fact that the HexSite® lessens the possibility of “fratricide”. This is defined as “the act of killing one’s brother or sister”, but our meaning would involve the accidental fatal shooting of a friendly brother-or-sister-in-arms – a fellow soldier, a fellow police officer, or an innocent -- in other words, an unintended target. Rationale: The unobstructive HexSite® allows eye focus which encompasses the entire target area. With both eyes open, looking through and not at the sight, focusing on the engagement area, the shooter’s expanded peripheral vision more effectively picks up the presence or approach of an unintended target. Result: Reduced risk of collateral damage by personnel with respect to refinement of target identification.
|
http://www.lwcbooks.com/articles/anatomy.html
Laur P. 4
****************************
OCULAR AND LUMINANCE ISSUES PERTINENT
TO OPTIMUM SIGHT UTILIZATION
By Daniel S. Lambert, PA-C
….. “In drafting this paper, I called heavily upon my medical training and experience in surgery and emergency medicine, but also upon my shooting experience, as well.” ….. “In that context, I state without any hesitation that, in addition, I have practiced extensively with the HexSite® Sighting System. Undoubtedly, in bonding my medical and shooting backgrounds in exercising the opportunity to apply the backgrounds to hands-on shooting with the HexSite®, has permitted an unusual perspective from which to generate an evaluation. |
….. “The human eye’s side-by-side position allows each eye a view of the same area from a slightly different angle. The eyes have a great deal in common, but one will pick up information that the other doesn’t, and these have to be mentally processed. Binocular vision results when the occipital cortex of the brain combines these disparate images to determine true stereoscopic depth. So, in a sense, a given object is seen in clearer detail at any ambient light value. With binocular or stereovision, we can more precisely see WHERE objects are in relation to us, especially when those objects are moving toward or away from us. We can see a little bit around solid objects without moving our heads, and we can even perceive and measure ‘empty space’.”
….. “With monocular vision, all of these capabilities are severely compromised, or eliminated completely. In monocular vision, there is a noticeable lag in correcting for luminance (light) changes when compared to binocular vision. In firearm shooting, this has real, not hypothetical, effects on rapid target identification and acquisition.”
….. “Relative optimal functional range of human vision within the ‘normal’ ambient light spectral range is high. That capability may not hold in situations where lighting is sub-optimal. Thus, it is always best, wherever possible, to present an object so that it, and it alone, holds the eye’s attention. Areas of highest contrast are visually acquired first. Some of the variables impinging on sight performance include the light intensity (including high/low contrast variables), and its relative angular incidence to both sight and target.”
….. “The HexSite® Sighting System, obviously designed to be used with both eyes open, preserves stereoscopic vision. This has utility in preserving depth perception, enhancing peripheral vision and, because of the enhanced light-gathering ability of both eyes, greater contrast definition of the target in all lighting scenarios.” The key point is that, in any field of regard, the eye focuses first on the higher contrast area.”
….. “This brings us to colored or ‘marked’ rear firearm sights. With such sight configurations, the distant object (target) will appear to blur because the brain is attempting to visually clarify the brighter (higher contrast) rear sight. Logically, in a mission-critical situation, the clearest field of regard should be the target, not the sight.”
….. “In the shooting environment, there are diverse independent variables operating in concert, which can allow the brain to correctly interpret what it sees. The shooter then takes the necessary steps to optimize his visual acuity, to accomplish correct target identification, and to shorten his target-acquisition rate.”
….. “The attributes of a functionally ‘ideal’ set of firearm sights ought to include provisions for non-obstructive (absence of bulk), binocular (both eyes open) vision, for (1) preservation of peripheral vision, for (2) realistic assessment of depth of field, and for (3) effectual function in low and bright situations.”
….. “The sights should provide these provisions simultaneously, and without creating ‘distractions’ that require the brain to make multiple decisions, thus slowing the shooter’s ability to acquire and engage the target. Again, sights frequently are marked with dots/paint/colors, presumably to enable the shooter to acquire faster sight alignment. But, in fact, these create a visually confusing picture (as described three paragraphs back). With focus drawn to sight ‘marking’, the brain has two mutually-exclusive choices:
- Settle for a clear sight picture at the expense of target clarity and peripheral vision; or.
- Take precious time to fight through the distraction, to gain a clear and accurate target acquisition.”
….. “The post-and-notch sight allows target refinement, but its bulk prevents a non-obstructive view of the target area. A circular ghost ring sight allows a non-obstructive view of the target area, but at the expense of target refinement.”
….. “The HexSite® is a hexagonal aperture sight designed for point-of-aim shooting, rather than a 6-o’clock hold, owing to its non-obstructive view of the target area. In a defensive situation, instead of employing the age-old conventional (and unnatural) instruction to “focus on the front sight”, the HexSite® allows the shooter to effectively employ a natural inclination to focus on the target. It is not a difficult conclusion to accept that this ‘unconventional mind set’ of always keeping the target in optical focus, not the sight, equates to significant increases in speed.
….. “Target acquisition is facilitated in large part by the geometry of the HexSite®. The shooter’s visual perception of the rear sight is of three consecutively smaller hexagonal edges, each centered inside the other, creating 16 intersecting-angle reference points.”
….. “These reference points draw the eye involuntarily to the precise optical center of the rear sight. In other words, the eye spontaneously is centered on the target without effort. Because the HexSite® is all black, the attention of the eye automatically is guided to the object of highest value beyond the sight – to the target.”
….. “Another distraction is eliminated by an angular, interior-face concavity at the rear of the rear sight, which reflects any incidental light away from the eye. This creates a ‘shadow’, further embellishing its ‘blackness’, giving the eye a maximum-value contrast in any light, drawing its attention, quickly and naturally, to the always-higher-value target area.”
….. “Note, in the above sketch of the HexSite®, the dotted lines connecting the vertices. These dotted lines symbolize the principle of ‘implied line’ (A-B-C) conceived by the brain as a result of the geometric reference points 1 - 16. The top center of the front sight post just touches and exactly bisects these lines. As a result, the shooter eliminates time-consuming consideration of extraneous variables, thereby significantly reducing target acquisition and engagement times.”
….. “Here we note that the ‘implied lines’, the 30-degree angular (B&C) and the horizontal (A) lines, conceived between vertices of the geometric reference points, also are used in refining elevation and windage, and in ‘leading’ moving targets. In executing these variables, the shooter experiences similar improvement in target acquisition and engagement times.”
Ocular and Luminance Issues Pertinent to
Optimum Sight Utilization by Daniel Lambert