The word “Reflex” in the term reflex sight is a reference to how the objective lens of the system essentially acts as a mirror, reflecting the targeting reticle or dot back to the eye of the shooter. This is why even though you may see a red dot, a laser is not being projected at all.
If you are looking for a reflex sight for your AR 15 rifle, it is important that you take the time to examine your options as well as look at all of the different factors that will be important in making your final decision.