What are Reflex Sights? Reflex sight vs red dot

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By Dennis Howard •  8 min read

Sights are a topic that often ends up in heated debates among shooters. One of the most discussed areas of firearms sights includes red dot sights, reflex sights, and holographic sights.

Many shooters use these three terms interchangeably, most notably red dot and reflex sights. In truth, there are some fundamental differences between the three types of sights that set them apart.

Most of the confusion comes from the similarities between these three sights styles.

All three often use a red or green dot reticle. Hence, the term “red dot sight” gets applied to all three almost indiscriminately. The difference lies in how the target and reticle images are transmitted to the shooter’s eye. While the end result is the same, the way it happens is not.

We will discuss the differences in the mechanisms used in all three of these styles of sights, but I am mostly interested in reflex sights. Reflex sights offer advantages and disadvantages to both holographic and red dot sights. A better understanding of how a reflex sight differs from its cousins, the holographic and red dot sights, is important when deciding which style of sight to mount on your firearm.

What Makes a Reflex Sight Different?

The major difference between our three sights styles is how the image of the reticle is created with the target image. How this process is accomplished produces many valuable characteristics of these sights, but there are some downsides with each one.

Let’s take a quick look at the mechanics used by each sight style to get that reticle image to your eye.

Tube Style Red Dot Sights

Tube style sights

Tube-style red dot sights work in much the same way as a traditional optical rifle scope. Light gathered by the objective lens is transmitted through the scope tube, where various other lens focus and invert the image.

Along the way, the reticle image is added to the sight picture before it reaches the ocular end of the scope and, ultimately, the shooter’s eye. In most cases, a light-emitting diode (LED) is used to generate the red dot of the reticle.

Holographic Sights

Holographic sights

Holographic sights are a rather recent entry into the firearms sight market. A holographic sight produces the reticle image by generating a holographic image three-dimensional image of the reticle using a laser.

This image of the reticle is then projected onto the viewing pane of the sight along with the target image. These rather intricate and complex systems usually make a true holographic sight more expensive than other sights, typically called “red dot sights.”

Reflex Sight Systems

Reflex sights are characterized by their simplicity. Very often, a reflex sight is nothing more than a lens onto which the image of the reticle is projected. This simple approach to creating the reticle image makes reflex sights very small and lightweight.

Many reflex sights are designed to be mounted on pistols. However, there are reflex sights that use a tube-style housing which often leads to confusion. These tube-style reflex sights tend to be used more for combat applications where extreme conditions are expected.

Many reflex sights offer brightness setting knobs that allow you to increase the illumination intensity when faced with a dark background

Where the Confusion Begins

The confusion is based on perceptions. Many shooters see a red dot in their sight picture, and whatever optical instrument they use immediately gets the term “red dot sight” attached.

Let’s make this clear: The terms holographic, reflex, and red dot sights are more about how the reticle image is generated than about the reticle image itself.

Not all reflex sights are red dot sights. Many project a traditional reticle or a specialized reticle. Some can produce various colors of reticle images depending on the user’s needs.

Reflex sights have certain characteristics that distinguish them from both holographic and tube sights. Once you understand these characteristics, you may better understand how reflex sights differ from other types of projected reticle sights.

Note: The luminous dot on reflex sights makes fast target acquisition possible a different distances making quick sighting an advantage.

How the Reflex Sight Builds the Sight Picture

In theory, reflex sights seem like very simple gadgets. When compared to holographic sights or traditional optical rifle scopes, they are uncomplicated.

In short, a reflex sight projects the reticle’s image onto a lens through which the shooter sees the target image. In most cases, reflex sights have no magnification built into the sight.

You must remember that reflex sights are not limited to red dot or green dot reticles. The image of the reticle can be almost anything, and many reflex sights feature proprietary reticle images for specialized applications. The defining characteristic of a reflex sight is how the reticle image is projected to the shooter’s eye.

Note: The dot size of a reflex sight can be important depending on the distances you shoot, the weather conditions, and the amount of available light.

What are the Advantages of a Reflex Sight?

Reflex sights bring many advantages to the table under the right circumstances. Like any sighting system, you must consider how you intend to use the sights, what kind of weapon you are shooting, and your expectation and needs. Shooters tend to mention these advantages of reflex sights most often:

Size and Weight

Reflex sights are among the smallest and lightest of all sight systems available for rifles and pistols. Reflex sights have made a profound difference in sight systems for pistols. The small, light reflex sight design can be mounted on the slide of most semi-automatic pistols and survive the recoil and action of the pistol operation.

Speed and Target Acquisition

When mounted on either a rifle or a pistol, reflex sights tend to allow quicker target acquisition than either traditional telescopic sights (tube sights) or iron sights. Iron sights demand you align three points to create the sight picture properly. You must align the rear sight, the front sight, and the target. Since these three points all lie in different focal planes, this can be difficult for some people with less-than-perfect eyesight.

A reflex sight requires only aligning two points, the red dot of the sight and the aiming point on your target. Since both appear to lie on the same focal plane, it is much easier to focus and must be less complicated. Less complication usually equals more speed.

Shooting with Both Eyes Open

The preferred method of shooting with a reflex sight is to keep both eyes open. This avoids the problems associated with tube-style sights and the “tunnel vision” syndrome accompanying the field of view limitations.

When you shoot with both eyes open and a reflex sight, you can see your target, and your aiming point, while your peripheral vision remains in play to keep you aware of a wider area.

Low Profile

Most reflex sights are red dot sights with a very low profile creating a much more compact installation on a rifle. A lower profile on your rifle means fewer snag hazards and a cleaner overall profile. Law enforcement and military personnel engaged in close-quarters combat chose reflex sights with red dot or green dot reticles for maneuverability and speed.

On pistols, small exposed reflex sights allow the pistol to be easily holstered and carried on a duty rig. Many civilian concealed carry license holders find that they can conveniently carry a compact pistol with a small red dot reflex sight mounted as a concealed firearm.

Use with Night Vision Devices

You can get a reflex sight that is compatible with night vision equipment, allowing you to use the sight in almost total darkness. These sights are great at short and medium distances when paired with night vision equipment giving you a definite edge after dark.

The Downsides – Reflex Sight Disadvantages

Nothing is without its problems, and reflex sights have their share. Before you switch to a reflex sight, it is important to consider problems that may occur and the challenges you may encounter in making the switch from telescopic sights to a reflex red dot:


Many reflex sights, especially mini reflex sights, can be easily broken or damaged. Reflex sights typically depend on the reticle image projected to the front lens, which requires the LED emitter to remain perfectly aligned. Sharp bumps, falls, or drops can knock this sensitive electronic part out of alignment.

The small housing necessary to maintain the lightweight and low profile also means there is less mass to protect the front lens. This lens reflects light to the shooter to produce the illuminated point. Damaging the front lens renders red dots unusable.


Magnification, or the lack of it, can be a downside that keeps many shooters and hunters from switching to a reflex sight.

In general, most reflex red dot sights do not magnify the target image. This makes reflex sight work limited to short and medium ranges. You can put a magnifier behind many reflex sights. Using a magnifier can produce 3X magnification of distant targets while allowing you to shoot with both eyes open at close range.

Reflex Sights – Specialized Equipment for Specialized Situations

Reflex sights are not for everyone or every situation. However, many shooters find that once they make the change, the concept of the illuminated dot in a reflex sight with adjustable brightness settings offers a whole new world of possibilities.

Whether you choose a reflex sight with a red dot or green dot sights, you will find that having both the target and the reticle easily seen and focused is a great advantage in fast target acquisition.

Dennis Howard

A life long hunter, fisherman, and outdoorsman, after surviving a devastating tornado in his home town, he saw the effects on people's lives as they struggled to cope. He built his first bugout bag a few weeks later and has been a dedicated prepper/survivalist since that time. After a career as a fireman, Dennis opened a retail store (FFL approved) catering to the military, law enforcement, and like-minded individuals. The store built their own AR platforms. Furthermore, Dennis was also an NRA instructor in both long gun and handgun as well as a certified range safety officer. Read his full interview here.