By Andre’ M. Dall’au
“Astigmatism does affect how some shooters are able or unable to effectively use certain optical sighting systems like a red dot or holographic sights.”
“A Red Dot sight that has had good remarks from people with astigmatism is the Meprolight M21. It is a compact 13.6 ounces with an excellent variable intensity reticle that is sharp and clear, especially in natural light”
Shooting is nothing more than placing a projectile on the desired target by visually aiming a firearm.
While the type, caliber, and size of the firearms, as well as the different types of aiming technology, are hugely variable, the common single constant is the use of the shooter’s eyes to match the location of where the shooter wants the bullet to go with its actual impact.
While shooters can talk volumes about bullet weights, argue specifics on ballistics, discuss the advantages of first focal plane telescopic sights and explain ‘‘minute of angle” six different ways, when asked about protecting their vision or how they take professional care of their eyes, you usually just get a blank stare or a shrug.
It may be ludicrous but some shooters who religiously keep their firearms cleaned and stored with care, use hours on the range to fine-tune sighting in a rifle or pistol, and spend hundreds on an optic or thousands on a “better” caliber rifle haven’t spent a dime for or seen an ophthalmologist or optometrist in years to protect the ONE variable that determines their ability to enjoy shooting!
Ouch, I know that hits home because as I was writing this, I realized I haven’t seen my ophthalmologist Dr. Geigerson in many years even though he saved my binocular vision twice before, so it’s not just you but all of us.
What Is Astigmatism?
When a newly purchased optical sight doesn’t work like advertised, or a red dot sight is blurry or indistinct, the shooter immediately wants to return the item accompanied by a strong letter of complaint to the manufacturer without ever thinking that the device may be fine, but it’s their eyes that have astigmatism.
It happens. But what is astigmatism? Basically, it’s when whatever you are viewing no longer focuses on the “sweet spot” of the retina but is slightly offset up or down or to the side, so you perceive the image as indistinct or blurry.
As per the American Optometric Association, astigmatism occurs when the cornea (the clear front cover of the eye) is irregularly shaped or sometimes because of a curvature of the lens inside the eye. It can be caused by mostly hereditary reasons but also can be age-related or caused by injury or medical conditions.
The good news is that it can be corrected by surgery or by glasses or contact lenses. While glasses are the simplest and easiest to use, contact lenses provide a wider field of view, and surgery can be used to permanently alter the shape of the eye eliminating the need for corrective lenses, but it carries the risk that any invasive procedure poses (and costs more.)
This is a conversation that is best had with your eye doctor who can knowledgeably discuss the options based on your specific eye health, refractive status, and medical and social history to choose the best match for you. Just like all those TV ads tell you, check with your doctor.
What Does A Red Dot Look Like With Astigmatism?
Astigmatism does affect how some shooters are able or unable to effectively use optical sighting systems like a red dot or holographic sights.
The red dot can appear indistinct, smeared, look like a starburst, or simply appear warped even by shooters who have 20/20 vision. Some reflex/red dot sights will be noticeably distorted while others will not, so picking one that is fuzzy may be corrected by just looking around and finding the one that literally suits your eyes.
A great place to start is to look for one with a larger MOA (Minute of Angle) dot. A larger dot lessens the blurring effect, so choosing a 4 MOA or larger may help. Secondly, reduce the brilliance of the dot so that it’s visible but not glaringly so that it minimizes the effect of the blur. Thirdly look at different colors.
While red is common, there are other options including green which is the very center of a human’s visual acuity and ability to see color and will help you focus. Being able to use iron or open sights to co-witness the red dot also can be used to reduce the blurriness of an illuminated dot.
How To Know If You Have Astigmatism (Or If the Red Dot Is Defective)
While only an eye doctor can properly diagnose if you have astigmatism, there are ways to help you know if it’s your eyes or if it’s a defective red dot sight. Take a picture with your cellphone camera of your red dot through the eyepiece of your red dot.
The astigmia-free picture will show the actual red dot image, so if it is blurry or malformed, it may be a problem with the red dot, but a distinct red dot in the picture – and you saw it blurry through the optic – oops, it’s not the optic.
Have a pal or wife/girlfriend (preferably both) look through the optic and without telling them what to look for, ask them what they see. If your pal, wife/girlfriend all see a sharp dot and you see it blurry, that’s strike two to getting a doctor involved.
You could also view the red dot through your backup iron rear sight to give a true image of what the dot actually looks like. Lastly while looking through it, rotate the red dot either clockwise or counterclockwise.
If the blurry or indistinct image persists and does not rotate as you change the orientation of the sight, then it’s not the sight. If the blurry or misshaped image moves with the rotation of the sight, ok, it’s back to the factory for the optic.
How To Use a Red Dot Sight With Astigmatism
OK, let’s say the results of your eye test are that you do have some astigmatism, how can you use a reflex/red dot sight? First, consult your eye care specialist about medical options available to you for your particular set of symptoms and circumstances to reduce or eliminate them.
Other non-medical remedies include the use of a larger MOA reticle (4 MOA at a minimum) and keeping the red dot at a low setting to reduce the optical aberration. That’s a good practice anyway to maintain your target situational awareness and less eye fatigue so you don’t have a bright red dot glaring in your eye, dilating your iris. Also, not every color of the rainbow is seen by humans equally.
The sequence of ROYGBIV (red/orange/yellow/green/blue/indigo/violent) is the natural pattern of the rainbow when white light is refracted through prism-like raindrops.
But each color is not seen the same, those colors actually are listed in order on a bell curve of optimum human visual acuity with GREEN at the peak. That means of all the colors, green is seen the best (which is why RED firetrucks were changed to GREEN firetrucks.) If a RED red dot sight doesn’t work as well as you want, try a GREEN red dot sight, it could be a surprising improvement.
You could also invest in polarized glasses which are basically a series of very fine lines that you filter your vision through and will reduce glare dramatically. Another option to reduce astigmatism distortion is to use prism or telescopic sights that use a lens and etched glass to produce the reticle.
The Low Power Variable Optic (LVPO) can be used close-in on 1X magnification but still has the capability of increased magnification for longer distance engagements, but is bigger, heavier, and less effective at shorter ranges than red dots.
The Best Red Dot Sight for Astigmatism
To determine which electro-optical sights work best for you is best determined by – well – you. There are some sights that can be used for effective shooting even if you do have slight astigmatism.
A red dot sight that has had good remarks from people with astigmatism is the Meprolight® Mepro M21. It is a compact 13.6 ounce with an excellent variable intensity reticle that is sharp and clear, especially in natural light. Meprolight® also offers a red dot style sight for handguns — the Mepro FT Bullseye™ Rear Sight or the Mepro FT Bullseye Front Sight.
Seth Rodgers in guns.com provided this comment about the sight “Finally, let’s talk about the FT Bullseye Sights. I can say that sight acquisition is quick and painless. These are possibly the easiest sights to pick up.
If you have astigmatism, as I do, then you may want to check out the (FT Bullseye sight) for this reason alone.” Both the FT Bullseye™ and M21 use fiber optics and tritium to light the reticle, eliminating the need for batteries. The M21 has an optional triangle reticle that shooters with astigmatism say that it really provides an aiming point superior to a dot.
The M21 offers larger reticles available up to 5.5 MOA so they are superior when looking for an optic to use with astigmatism. There are lots of choices available from Meprolight® that can help every shooter, so for more information please view Meprolight.com.