A true red dot sight such as an EOTech is acutally a holographic projection. This class of optics are known technically as Holographic Weapons Sights, usually shortened to "HWS". Just because it's interesting I'll try and give a brief summary of how holographs came about and how we can now buy one to put on top of a gun.

Simply defined, holography is an optical process of wavefront reconstruction of a three dimensional object by recording the interfering pattern of light. The concept and theory of holograms was defined in the late 1950s in a paper published by Dennis Gabor (a paper that would subsequently lead to a nobel prize for him in that area of study) but it wasn't until a few years later in the early 1960s that the availability of a stable source of light in the form of a helium-neon gas laser allowed the theory to be applied in the creation of the first hologram. The scientific community, as well as the rest of the world, was astounded by the ability to reconstruct a three dimensional object in waveform.

Fast forward to the early 1990s where the cutting edge, labratory sized lasers used in the 1960s experiements can now fit inside your fist and can be produced extremely economically. This advancement was one of two that made the modern holographic gun sights such as EOTech possible. The other was the development of holographic heads up displays (HUDs) for fighter aircraft.

This second advancement was perfected and implemented by the early 80's and put to use in advance fighter aircraft at the time. The holograms in these systmes were of very high quality and allowed the pilots to effeciently gauge readings as well as quickly acquire targets.

In 1995 with these two sucesses to build off of EOTech was formed as a subsidiary of ERIM to re-assess the possibility for holographic weapon sights for small arms. EOTech managed to sucessfully shrink the larger systems being used on helicopter gunships and anti-aircraft batteries to a compact and rugged sight similar to the one we know today. By January, 2000 the second generation Holosight was released to the consumer market.