DI Optical’s EG1 Review: Thinking Outside the Box with a Box


Aimpoint is the only serious dot sight that anyone recommends anymore, right? Right. With the death of EOTECH’s reputation, we are left with option A for a serious duty ready red dot sight. Well, that would be the case had not D I Optical stepped into the American market. Can DIO fill the gap and bring in a quality product that gives consumers a second option to consider aside from Aimpoint?

New to the Market, Not New to the Game

If you aren’t familiar with DIO, the RV1 is the Americanized version of their service rifle red dot sight, and DIO has been making red dots of all sizes for years. See NSN# 1005-01-626-1714 for their Heavy Machine Gun Sight which is in service here stateside.

My first hands on impression with DIO was with their RV1 red dot, which I reviewed at my own blog a few weeks ago. Reaching out to DIO to show them that I beat their little red dot up and it survived, they propositioned me to beat on their EG1 red dot like I did to the RV1. I agreed.

So I took it out to the ranch, sighted in off the co-witnessed iron sights, and got to work. I threw it down multiple times, and attempted to drown it several times, and did my best to make it break. No dice. No Drama. The dot stayed on and nothing construction wise was amiss. The only problem I encountered was a loosening of the mount screws… and this was a self-made problem. I should have loc-tited it down before I even mounted it. I know better. Once I noticed that it was loosening, I ran into my shop, torqued the screws back into place, and my zero came back, and I kept on shooting. (PS: My Geiselle Mk4’s screws also started to loosen, so keep that in mind. Yes, I beat my gun that bad testing the EG1).

[youtube https://www.youtube.com/watch?v=vUh4c5eXDHg]

So with the beating, the drowning, and the overall slapping around, the EG1 performed like a red dot should… bright and always on. One of the key features of the optic is the unique form factor. As you can see, it is a square body with a square-ish 28mm lens. This unique configuration is made possible due to the prism assembly which allows the emitter to be smack dab in the base of the optic. As the emitter shines upward from the base, it is redirected by the prism to the shooter and it allows the DIO to maximize lens real estate without the emitter assembly getting in the way. Thinking outside the box with a box. It’s just crazy enough to work. I like it.

It features a battery life of 5000 hours at a medium setting… lets see, 15 total brightness settings divided by two… well let’s call that setting 8, we will round-up. The side of the optic has the windage and elevation adjustments and comes with a handy tool to adjust them, though a dime would work just the same.

It’s also mil-std 810G environment tested so we have some certification that we are getting a optic which passes some testing standards unlike many of the Chinese products on the market today. The mount itself is held in place by two hex screws, and they are big and beefy. The optic is compatible with ARMS #17 style mounts, so you have plenty of options for trading out the finger knob.

The sun shades are removable, so you can enhance the view even more. I noted that the optic is not sensitive to placement. There isn’t a “tube effect” like the Comp M4 or the mini RDS when they are mounted too close to the eye. The EG1 is just a wide open eye box. I ran it close to the rear BUIS to reduce over-the-shoulder sun glare if the heat was at my 6.


Impressions are good. This optic retails for just north of $400 bones and that is precisely in Aimpoint Pro territory. For a relative newcomer to the US market, the EG1 represents a very different approach to the RDS and its use of a prismatic assembly to widen the field of view is a novel concept. With my two DIO red dots in hand, I must say that I have started to recommend them on the forums I haunt. I hope to see more of DIO’s products in the future, and hopefully they can continue to innovate in the red dot market and add some much needed competition.


    • It’s gained a following, but the internet echo chamber seems to scream Aimpoint the loudest when we could get some excellent alternative products that leave us with enough change to buy some ammo.

  1. The fact that Socom and JSOC haven’t stopped using Eotech should make people stop thinking Eotechs aren’t a viable option.

    • I guess that makes it ok to make fraudulent product claims. As long as special forces uses it. I said that their reputation is in the toilet… despite whatever fixes they may have implemented to correct their product. Reputation and trust is a big deal in this industry, and a very small minority continues to recomend eotech after the fallout of their lawsuit. Most shooters point to aimpoint as their numero uno recomendation.

    • If you have uncle sam’s checkbook and few moral qualms, sure. JSOC et al just replace them when they die. As an infantry PL, every single eotech we had died. Every one of them. Needless to say, that’s sullied their reputation for me. They’re a disreputable company that cared about profit over integrity, willingly hiding flaws from those who literally bet their lives on their equipment. But yeah, other than breaking and utter lack of integrity, great outfit.

  2. So, is this a prismatic sight? I have (what I assume is) astigmatism in my eyes and red dots appear to me as a smear.

    • I have one, and I bought it largely because I have astigmatism and I read it’s a prismatic sight. Maybe it technically is, but I can personally verify that the EG1 red dot looks like the red dot on an Aimpoint to my astigmatic(?) eyes – like a bunch of grapes, not a single dot. Apparently the brightest grape is the right one… Nonetheless, it’s such a good optic that I kept it anyway. Zero tube effect when keeping both eyes open, and zero color or background brightness shift through the glass (unlike my Aimpoint or Vortex 1x optics) and has a cleaner and smaller dot than my JPoint reflex sight. Plus it looks cool. I have a Vortex Spitfire 1x prismatic scope which looks perfectly sharp even with astigmatism, but I don’t get that effortless red dot feel when I shoot it with both eyes open. So astigmatism sucks, and red dots are really the way to go for fast both eyes open shooting. And the EG1 is a great optic even though it looks wonky if you have astigmatism.

  3. You seem to be forgetting about the Trijicon MRO, which is from a VERY reputable manufacturer, has the same battery life as the Aimpoint T2, while being almost as light and with a sharper, wider field of view. Also, it has survived the same torture testing as the Aimpoint, and its 7075 T6 forged body makes it the strongest option out there.


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