What Is A Red Dot Sight?

Unless you are a first-time gun owner, chances are you have heard of a red dot sight before. However, most people don’t actually know what this type of scope is. After all, there are many different types of scopes and sights available for every gun. In this post, we’ll help you answer the question: what is a red dot sight?

Red Dot Sights 101

picture of two different red dot scopes

Invented in the mid-70s, red dot sights are a type of non-magnifying reflector sight. In other words, they allow the user to see a red dot when looking through the scope to acquire a target.

However, unlike many of the popular scopes today, the red dot sight works without any magnification. This makes them ideal for close-range shooting. However, you can also equip one of the best red dot magnifier devices to add magnification to your optic! 


The inventions and advancement of the red dot optic made shooting much easier. This is mainly due to the fact that shooters no longer need to form a proper sight picture by aligning the front and rear sights to acquire a target. With a red dot sight…you simply place the dot on the target and fire.

With advancements in technology, red dot sights are now highly durable and can withstand a great deal of recoil.

Takeaway: When looking into a red dot sight, a red light is used to acquire your target.

How do red dot sights work?

Red dot sights do not use any groundbreaking technology. Glass & light is all that is needed to create a red dot reticle.

Most red dot sights use a spherical mirror that reflects the light emitted from an LED. The LED is positioned so that the light will bounce off the mirror and into your eye. The result is a bright, reticle that appears to be floating in mid-air.

diagram of how a red dot sight work

Red dot sights work by using an LED to shine a beam of light onto a specially coated piece of glass. The glass is angled so that the light is reflected back into the optics of the sight. Many dot sights give you the option to choose between green and red dots. If you plan to shoot in bright light conditions, we recommend you go with green. If you have an eye condition, you also need to choose between green vs red dot Astigmatism.

Different Sizes

If you are familiar with red dot sights, you will often see the word “MOA” labeled on each sight. MOA stands for “Minute of Angle” and is a unit of measurement that is used to describe the size of the reticle at a given distance. Most people choose between 3 MOA and 6 MOA depending on their goals. However, there are actually 3 different dot sizes.

  • 1 MOA – The dot sight will appear to be 1″ in diameter when scoping a target at 100 yards.
  • 3 MOA – The dot sight will appear to be 3″ in diameter when scoping a target at 100 yards.
  • 6 MOA – The dot sight will appear to be 6″ in diameter when scoping a target at 100 yards.

If you plan to primarily shoot at close-range, a 6 MOA dot sight will be your best bet. However, if you plan on shooting at a long-range, 6 MOA will not be as precise. The dot may be larger than the target at that range! Go with a 1 MOA or 3 MOA red dot sight to shoot more accurately at longer distances.

Different Types Of Red Dot Sights

There are three primary types of red dot sights:

  • Prism Sights – Prism sights use a glass prism to flip the image right-side up, so you don’t have to worry about inverting your scope. They don’t use a traditional dot reticle. In fact, in our post on prism vs red dot sights we saw that most prism sights have the reticle etched into the glass itself.
  • Holographic Sights – Holographic sights are a type of optical sight that uses a laser-transmitted hologram of a reticle shown in three dimensions. This allows the shooter to see the reticle without having to align their eye with the sight. Holographic sights & red dot sights do not use magnification.
  • Reflex SightsReflex sights are a type of red dot sight that uses a light-emitting diode, or LED, to project an aiming point – the dot – onto the target. The shooter aligns the dot with the target and pulls the trigger. If you’re interested, check out our article on the Best Reflex Sights for A Shotgun.

Choosing Your Sight

If you are in the market for a brand new red dot sight, you need to consider a few things:

  • Your budget
  • Dot color & size
  • Type of sight
  • Use case of the weapon

If you want to see a list of quality sights, check out our posts on the Best Red Dot Sights For An AR-15. And if you are operating on a tight budget, review the Best Red Dot Pistol Sight For The Money! Our buying guides are designed to make shopping seamless for our readers.

Use Cases

You now know the technology behind red dot sights, but when do we use them?

Red dot sights are often used on rifles, shotguns, and handguns. However, they can also be used on paintball guns and airsoft guns. No matter which type of weapon you shoot with, a red dot sight can improve your accuracy.

After all, there is a reason why red dot sights are so popular in military and law enforcement applications!

How To Aim

Here are a few tips to help you aim your red dot sight like a pro:

  1. Make sure the red dot sight is properly mounted on your firearm & zero your sight. This just means adjusting the windage and elevation screws until the dot sits where you want it in relation to your barrel.
  2. Place the dot on your target and squeeze the trigger.
  3. The key to accuracy is maintaining a consistent sight picture, so don’t take your eye off the target while you’re pulling the trigger.

Shooting with a red dot sight is far from rocket science. Like any skill…you need to practice!

What Maintenance Do Red Dot Sights Require?

Maintenance and care of red dot sights involve several important aspects. Taking to properly clean and protect the sight lens is crucial to ensure optimal performance. Use a soft cloth or lens cleaning solution to clean your sight after each use. Allowing debris to build up on your optic can affect your sight picture and shooting performance.

Rubber lens covers can also be a very simple solution to preventing dust, debris, or moisture from accumulating on your optic.

Red dot sights also require shooters to take care of their batteries. A shooter should monitor battery life and replace them periodically to avoid sudden power loss. Although each red dot battery should last for over a year when used on normal brightness settings.

Finally, there will always be random issues that occur with certain types of red dot sights. If your optic has any problems such as flickering reticle, loss of brightness, or alignment issues, check out the manufacturer’s manual or contact customer support. Applying common sense & simple periodic maintenance can go a long way to preventing any serious issues with your red dot & increase it’s longevity.

Any Downsides?

Getting a new red dot sight won’t cure all your problems. In fact, there are some downsides you should be aware of before buying your own.

  • Cost Money – This may be obvious, but we don’t all have the budget to buy countless gun accessories. Trust me… I’ve been there.
  • Lose Zero – If you use your weapon in rugged conditions, your gun may lose its zero over time. As a result, you will need to recalibrate to make sure you’re shooting with accuracy.
  • Battery Life – Most red dot sights are battery-powered. This means they can die, sometimes at the most inconvenient moments! Be sure to charge your sights when not using them. Learn how to turn your red dot sight off to save some battery!

FAQs – Red Dot Sights

What are red dot sights good for?

A red dot sight is a good option for someone looking for better accuracy and easier target acquisition. Red dot optics don't require perfect alignment, so they're faster and easier to use. When using iron sights instead of red dot, the shooter has to alight the front sight and rear sight. A red dot sight makes the aiming process easy.

Are red dot sights better than scopes?

Red dot sights are becoming more and more popular on rifles because they are lighter and smaller than magnified scopes. The downside is that most red dot sights don't work as well in low light conditions, and they can be harder to aim accurately over long distances.

What is the difference between a red dot sight and a laser sight?

A laser sight is a type of optical sight that uses a laser beam to illuminate a target. A red dot sight is another type of optical sight that uses an LED (light-emitting diode) to create a red aiming point. Laser sights are visible to the enemy, but a red dot optic can only be seen by the shooter. Red dot sights are generally more expensive than laser sights.

Do red dot sights work at night?

Red dot sights work very well at night because the illuminated red dot stands out against most backgrounds. The reticle (the little red dot) is also very small, so it's easy to keep your eye on it even when you're moving around. The same can't be said about standard iron sights.

Why do people like red dot sights?

One of the main reasons people like red dot sights is because they can be used with both eyes open. This allows for better situational awareness and faster target acquisition. Another reason is that red dot sights often use no magnification, so there is no need to align your eye with the sight picture. They are also very compact, making them great for close-quarters situations.

Are red dot sights accurate?

Most shooters find that red dot sights make them more accurate. The reason for this is that red dot sights allow the shooter to more easily acquire their target. Iron sights often obstruct the view of your target downrange. This means that the brain has more visual information to work with when aligning the shot, and thus the shots tend to be more accurate.

How far do red dot sights work?

In the case of the red dots without any Red dot sights are usually effective up to 100 yards. At distances beyond that, the drop of the bullet becomes too significant for the red dot sight to be accurately used. If you are shooting primarily long distance, I recommend using a 3 MOA dot sight.

The Bottom Line

By now you should be a red dot sight expert. From my own personal experience, I know that these sights are money well spent. They can improve the accuracy and confidence of almost any shooter. So get out there are test some new dot sights. Let us know which sight works best for you!

About the author

Patrick Howard

I have been working as a gunsmith for 20 years. Rain, fog, moisture, high temperature, or even snow are all the things a product must withstand in order to be recommended by me.

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