Red is an irritating color to the human brain. Red grabs our attention, which is why stop signs, red lights and sports cars all are bathed in it. Irritating doesn't always mean a bad thing. In reference to gun sights, red is quick for the eye to pick up, for the brain to process and contrasts against almost every background, which makes it easy to distinguish red hues in the visible spectrum.
Besides fiber optic sights, red is almost exclusively used in miniature reflex sights as the dot reticle. It's so common, in fact, that "red dot sights" has become the collective label for this optic category. Compared to other colors, red LED emitters have been all but perfected, as they now require less energy to run for longer durations between battery changes. Red dots have proven to be very durable and resistant to the stress of recoil impulses generated and transferred after a gun is fired.
The color red isn't without drawbacks, however. A red dot can appear harsh to some eyes, and tends to bloom and create aberrations or flares as the intensity is cranked up. Like staring into a bright light, some human eyes don't perceive or are not as sensitive to the color red.
One-in-twelve males have some degree of red/green color blindness. A red reticle may appear fire engine red to one person, while the same is processed by the brain as a light orange. Shooters with aging eyes lose the ability to focus on fine points as well as the color red to a certain degree. Further, older shooters generally see green more consistently, as green is more forgiving to the unfocused eye.
Green isn't just for aging eyes, either. The human eye is more sensitive to green and can see more shades (i.e., tones) of it than any other. Green is a cooler, calmer hue that the eye immediately recognizes and is not irritated by. The rods and cones within our retina process green better than red, especially in low-light conditions. Think about how you acquire a sight picture in changing lighting conditions. Moving from a light room to a dark room, your eyes try to adapt.
Trijicon has been offering green reticles in its fiber-optic based sighting systems for several years. However, Trijicon is just now entering the green LED market and it begins with the award-winning MRO.
Why now? In a nutshell, green LED technology has advanced during the last two years. They can now make them small and robust enough to withstand the abuse of a firearm. Simply put, Trijicon is now willing to stand behind green dot sights.
Not All Greens Are Created Equal
Like all colors, green is available in many tones. Trijicon chose to equip its new MRO with a green color on the spectrum at 575 nanometers (nm). Green can be described by a color number. A bluish green, for example, would fall in the 480nm range, whereas leafy, light green tends toward 500nm. It appears as a yellow-green color near 580nm. The 575nm that Trijicon uses is not yellow. Rather, it closely resembles the green found in green phosphate night vision devices. It stands out well against green foliage.
Trijicon also changed the color of the lens with green dot MROs. They use a notch filter that reflects back a specific color wave length to the eye that allows the user to see a clean, crisp dot. The lens has a slight purplish tint, but is less obvious than the bluish coating seen on the red dot MRO. While the glass is clearer, Trijicon didn't change the len's prescription. Parallax performance remains the same.
Battery life is half of the MRO red dot. On setting 3 of 6, its battery lasts 1 year. Because green LED tech is not as advanced as red, green LEDs are driven harder, which requires more power. The green MRO is not temperature sensitive, however, and will operate in the range of -60oF to 160oF and is waterproof to 30 meters.
I like Trijicon's 575nm green dot a lot. I can't wait for a green RMR.