Results of the Red Dot Position Survey

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Greetings Shooters,

"Thank you!" to all who took the time and participated in this survey. To those who chose not to participate, may your pants drop while shooting a Rapid Fire string during a match, and according to the latest NRA Rulebook, this would not be an allowable reason for an alibi. Kidding aside, a few key observations were noted and two important pearls resulted from this survey.

Are we seeing correctly or not, and does it matter? For those who emphasize the importance of trigger control, this may be considered a non-issue, and this survey was not intended to determine if we "concentrate" on the dot or the target. We only wanted to find out if we were "focusing" the red dot in front of the target or in the same plane.

We had a total of 116 valid responses for this survey. The oldest responder was 76 years of age and the youngest was 28. There were 3 female responders. The following were the results:

Age was not a determining factor because there were older shooters who saw the dot closer, and other older shooters who saw it in the same plane. This was also true with the younger shooters. I wish to extend my admiration to those shooters in their seventies. The total breakdown in overall ages were:

Ten percent of the responders reported having cataracts in both the "YES" and "NO" categories. There were 4 shooters with diabetes and 5 shooters who underwent refractive surgery and they were divided among the three groups. These conditions had no bearing to the results of this survey.

How well one shoots was also not a factor either because we had top national shooters in both categories. Their participation in this survey was significant. Two national record holders responded "No" and a third responded "Not Sure." As we know, the seven time national champion, GySgt Brian Zins, sees the dot in front of the target.

Most responders had a recent eye exam, within a year or two. Of those who saw the dot in front of the target, only 61% reported that they thought they were seeing their best. However, a smaller percentage was reported for those who saw the dot in the same plane, only 46%. In the "Not Sure" category, this figure decreased to 40%. Although a larger sample would have been more desirable, these numbers would appear to be important.

As we expected, Ultradot was the most popular brand of scope used by our responders. There was a slightly larger percentage of Ultradot users who saw the dot closer than the target, at 83% for the "YES" responders, while 70% for the "NO" responders, and 68% for the "NOT SURE" responders. Brands other than Ultradot in the "NO" and "NOT SURE" categories included Adco, Tasco, Docter, Aimpoint, Simmons, Bushnell, Gilmore, Leopold, Salyer, and Nikon. A larger sample may have proven or disproven the significance of the Ultradot brand. However, there was an equal 5% across the 3 categories who used other brands of scopes along with their Ultradot.

There were 7 shooters in all who used the 2 moa size dot and 7 shooters who used the 12 or larger moa dot, although not always exclusively. The overwhelming majority used the 4 or 8 moa dot or similar in size depending upon the scope brand. Size of dot was not a factor in the judgment of dot position in relationship to the target.

There was one "No" and one "Not Sure" responder who reported that perhaps lighting and the use of filters may have had some effect on the dot position. However, none of the "Yes" responders said lighting was a factor nor the intensity of the settings.

A shooter from Wisconsin reported that he sees the dot in front of the target only when both eyes were opened with no occlusion to the non-shooting eye. When occluded, they appear to be in the same plane. True depth perception requires binocular vision, the simultaneous use of both eyes. Each eye would view slightly different angles of the objects and the brain would extrapolate the distances and evaluate the depth perception. With both eyes opened, only one eye would actually be seeing the dot. I would postulate that when both eyes are focused onto the target, the overall focusing was more stable and more exact. The forward position of the dot was then more pronounced for depth judgment with the eye seeing the dot.

With only one eye focused onto the dot and the target, this would typically give a feedback of flat depth perception. However, respondents have reported that "forced focus" (accommodation), would bring the dot into better clarity. This would suggest the dot to be closer than the target. Shooters have measured this distance as approximately 30 feet, by using a single lens reflex camera to refocus the dot. One such article was written by John Dreyer, entitled, "Facts and Figures About Dot Sights." I also confirmed this measurement while using the same type of camera.

The First Pearl:

An unexpected finding as I was experimenting, was that this 30 feet distance was NOT absolute. In other words, the dot focal distance changed as one focused at different distances. When we focus onto targets at different distances such as 50 yards, 50 feet, 10 feet, and at two feet, the dot focus would continually change in relationship to our focus. It does not stay sharp at 30 feet if we focus much closer. Try looking at a calendar positioned one to two feet away from your scope and note that the red dot would still be in focus (or slightly closer than the calendar). If the dot was always focused at 30 feet, it should be blurred as we look at the calendar, but this would not be the case.

Why would the majority of the responses indicate that the dot was focused closer than the target? My observations and conclusions in my article, "Red Dot Focusing Position" would seem to be confirmed.

Colors of various wavelengths will focus onto our retinas in different positions, and this is known as "Chromatic Aberration." Red happens to be focused beyond (behind) our retinas, and forced focus (accommodation) is needed to bring red into clearer focus onto the retinal surface. When that happens, the target will then become slightly out of focus. The amount of refocus is not much, only a fraction of a diopter. This is graphically demonstrated by the RED/GREEN (Duochrome) test at your eye doctor's exam room. One responder of the survey experienced this test during his eye exam.

Whether we look at distant objects or near objects, these objects will be focused onto our retinas with good accuracy (with prescription lenses when needed). There would then always be a lag with RED color wavelengths onto our retinas. Interestingly, chromatic aberration would also occur for those who are "color vision deficient," commonly known as color blindness. Clearly, 60% of our responders saw this lag which was described as a perception of the dot being closer than the target.

The Second Pearl:

As I was checking the red dot focus in different environments, I also tested the dot focus in an indoor range, and probably noticed the same problems most of you have experienced and had described in your surveys. Poorer vision resulted with the dimmer lighting and at the closer proximity. Larger pupils while shooting indoors resulted in "spherical aberration," as described in the article, "The Ideal Pupil." Although my eyeglasses were current and my vision was great for outdoors, I couldn't see the red dot at the 50 feet indoor range very well. It was just too distorted to view with any confidence. The dot was distorted with all size settings. An aperture would help clear the dot, but knowing that the dot would be focused closer than the target, I put on an older pair of eyeglasses and there was instant transformation back into a sharp and round red dot. What solved my problem was +0.25 over my new eyeglass Rx for the 50 feet indoor range.

Click onto the link again and review my article, "Use of Obsolete Eyeglasses as Shooting Glasses." Although this article was written in reference to iron sights, the same principles would apply. In this case, a 0.25 diopter less power in my nearsighted prescription made all the difference in the world. Consider this as a caution for shooters when we have our eyes examined by our eye doctors. There are some in the eye care profession who think a change of 0.25 diopter as negligible. I assure you that this was not the case. For those who are nearsighted, you might want to try 0.25 diopter less power. Those who are farsighted, try 0.25 more power to improve your vision while at the indoor range. This will probably apply to those who have current eyeglass prescriptions, used as a baseline. Will you see the dot better? I did. Will you shoot better? That's up to you.

Those who have Champion Shooting glasses or the Knoblochs may have the means to experiment with different powers when at the indoor range. If not, look for those older eyeglasses tucked away somewhere. If none are available, then a separate prescription shooting glasses will be needed for the indoor range if good vision is important to the shooter. This pearl may help your eye doctor during an eye exam.

There was one problem discovered from this survey which was abundantly clear, and that was, a fairly large percentage of shooters were not happy with their vision, even for those who reported no ocular health problems and had a recent eye exam within 6 months. One responder wrote that she would welcome a doctor referral list that I had mentioned before. I will attempt, at a later date, to compile this referral list of eye doctors who have been recommended by listmembers. I will be asking for your help, once again. These eye doctors will have the patience and expertise to examine your eyes properly. It gives me satisfaction when shooters improve and that I may have been a help.

There would be justification for those who wondered why I didn't include many more questions in this survey. Well, this survey was a learning experience for me also and I felt that the more complicated the survey, the less likely would be the responses. I think that the basic question was answered, and that was, the percentage of those who see the red dot in front of the target.

For those who responded "No" or "Not Sure," try to force your focus onto the red dot and perhaps you may see what 60% of the responders also saw. Prior to this topic brought about by GySgt Brian Zins, perhaps some of you in these two categories may not have taken a really good look and evaluated the red dot. I know that I didn't. Perhaps a second survey in a year or so may fine-tune your responses. When time permits, I will be answering individual questions on the surveys asked by the respondents, off-list.

Good Vision and Good Shooting to All,

Norman H. Wong, O.D.

Camp Perry National Matches - 2004