Astigmatism is something that a lot of shooters struggle with. In fact, one in three people have some form of this problem to some degree. Today, we're going to look at an optic that helps to mitigate the effects of astigmatism: the prism optic.
First though, a brief overview of astigmatism. Put in simple terms, astigmatism is when one part of your eye has a different shape from the other. This difference in shape can be either in the cornea or the lens, it doesn't really matter. What matters is that the two shapes don't really match. Think of an egg holder tray. The shape of the tray sometimes doesn't fit the egg that you put in the tray because the two surfaces don't match exactly. This is roughly how you could picture astigmatism: the two main parts of your eye don't match exactly.
So what happens when you have astigmatism? For those of us in the shooting world, this most readily presents itself with red-dot optics. When looking through a red dot optic, shooters with astigmatism won't see a clean or crisp red dot with defined edges. Instead we see a starburst or a blurred dot or in some cases even a duplicated phantom dot. This obviously is not ideal for the sake of any sort of accuracy.
Prism sights negate this by using a different method altogether for delivering the dot or reticle to the eye. Instead of reflecting an LED light off of a piece of glass, a prism sight uses lenses inside the housing to bend and rotate the reticle image. The net result of this is that the image displays clearly and cleanly for all eye types.
That brings me to todays review: the Swampfox Blade prism optic. Regular viewers may have noticed that I'm on a bit of a Swampfox kick lately; I recently reviewed the Justice red dot, and unboxed the Justice/Ironsides combo for use in an upcoming series. This is my first experience with a Swampfox rail-mounted optic, however.
The Blade is a 1x25 optic that uses prisms to display its etched and illuminated CQB-oriented reticle. Swampfox calls that a "bullet rise compensation" reticle; more on that in a moment. It also features the same shake-awake technology found in the Justice, and it has 10 illumination settings for the reticle, two of which are night vision settings. It has a focusing eyepiece for tuning the reticle to your eyes, and 3.8 inches of eye relief. The MSRP for the Blade is $240, which already makes it very affordable for what it is, but can consistently be found for less than that. I got this one for $200 at Brownells.
The Blade runs on a CR123 battery that is included with the optic. Swampfox quotes an operational life between 3000 hours on the low end to 40,000 hours on the high end. Considering that auto-off and shake-awake features that the optic has, this should be more than enough time to last a full year for my use case, which is when I typically change my batteries. The illumination setting is controlled by the up and down buttons on top of the optic, and I found these to be easy to find and use.
The Blade has a total available range of 45MOA of adjustment, and is adjusted via turrets on the top and right side of the optic. Each click has a 0.5 MOA per-click adjustment. The turrets are covered with turret caps that are sealed with o-rings, and are secured to the body with tethers.
All of this is housed in a 6061-T6 aluminum body measuring 4 inches by 2.4 inches by 3.03 inches. This includes an integrated picatinny rail mount that puts the optic at cowitness height for an AR15. The Blade is rated as IPX7 waterproof, which means it will survive in 1 meter of water submersion for 30 minutes. Swampfox also claims the Blade is fog and shock-proof.
Swampfox throws in lens flip covers and a honeycomb killflash in the box, which is nice. Also in the box are the standard Swampfox documentation, lens cleaning cloth, and adjustment too. The Blade also includes another wrench specifically for the mounting screws.
As I mentioned, the Blade's reticle is a "bullet rise compensation" reticle. According to Swampfox, this reticle has been optimized for home defense and law enforcement use. The compensation that they mention is to compensate for height-over-bore for AR-pattern weapons; in a practical sense that means that once zeroed, the Blade has dedicated holds on the reticle for 5, 10, and 15 yard distances. The chevron at the bottom of the reticle is a 5-yard hold, the dot above that is the 10 yard hold, and the base of the arrow is a 15-yard hold. It should be noted again that this is for AR-pattern firearms; Swampfox says that the holds will not be as valid with other weapons systems.
I've had the blade mounted to my 10.5-inch AR pistol for a few months now, and I have a few opinions on it. First and foremost, it has held zero for about 700 rounds with no issues, and has always been powered on as advertised when I pick up the weapon. I also think that the prism optic is a godsend for people with astigmatism. The reticle on the Blade is always clear and bright, and because it's etched into the glass, it's always there even with no illumination turned on. The illumination itself is clean, evenly dispersed, and gets plenty bright for daytime use. The dedicated holds are fantastic for close shots because they let me zero the weapon at a still useable 50/200 yard while still giving me an actual point on the reticle to put on a target at much closer ranges. I also like that the battery compartment is in the middle of the body, which makes the optic less bulky. I like the integrated cowitness mount for AR-pattern weapons. I like that they take the time to include accessories like caps and a killflash in the box so you're ready to go with nothing else to buy.
Now for some things that maybe aren't so great. I will say right off the bat that most of these are small things. That being said, the first thing I'll note is admittedly a small nit to pick: I think that the included flip caps are really not very good...or at least the one for the eyepiece is not very good. It seems like if I don't flip it closed certain way, the entire cap will come off of the optic. Similarly, sometimes if you don't open it a certain way, the cap will come off the optic. I love that these are included in the box, but they need to fit more snugly to be fully functional. Second thing is turret adjustment, and the lack of a distinct tactile "click" for each adjustment. The turrets do make an audible sound when they adjust, but its pretty quiet and I can confirm that are inaudible on a range with other people shooting. The fact that I couldn't really feel a "click" when I adjust the turrets had me second-guessing my adjustments and added extra time to zeroing the optic. Lastly, the eyebox is notably smaller than a red dot when you're off-axis a bit, and I noticed that some of the fins on the included killflash were bent out of the box.
So what do I think overall? I think it's pretty darn good. The feature set and performance are hard to match at this price point. The only thing that currently comes close is the Vortex Spitfire AR, and that lacks the bullet rise compensation reticle and auto-on features that the Blade has. There are definitely some small annoying things about it, but they're not things that have stopped me from running and enjoying the optic. Currently I have the flip caps removed and the optic zeroed at the recommended 50/200 distance, and not having to deal with the caps or dial in the turrets has eliminated most of my complaints about the Blade. That, and the fact that I don't have to deal with the typical problems associated with astigmatism and a red dot optic mean that I think that this has found a permanent home on my 10.5 inch pistol, and has gone a good bit to give me a good impression of Swampfox as a brand.
So that's the PT review of the Swampfox Blade, and how it helped solve (at least partially) my struggles as a shooter with astigmatism. If you're interested in the Blade, you can check it out at Brownells. That's all I have for you this time; stay tuned for next week's post for an intro to yet another series! Until then, Stay safe!