Pistol Night Sights: How Do They Actually Work?

Many years ago, I created pistol sights by dabbing a phosphorescent powder mixed with clear glue onto the white dots of the standard pistol sights. It worked well enough; however, I had to frequently “re-charge” the dots with a light source to make them work effectively. Thankfully technology has fortunately advanced in leaps and bounds. Specialty items like tritium-based night sights are now commonplace and available for most pistols, but how do pistol night sights work?

Pistol night sights work by phosphorescence. A chemical reaction creates the illuminated dots on a pistol sight.  The inside of a glass tube is coated with luminous material and tritium.  Over time the tritium decays and releases electrons. Electrons excite the tube’s coating, creating fluorescence.

Law enforcement and the military have seen the advantages of night sights and now require all new pistols to be fitted with night sights as standard. Fortunately, civilian firearm owners also have access to this technology. By understanding how night sights work, pistol owners can knowledgeably select the best sights for their weapon.

how do night sights on a pistol work

Pistol Night Sights, What Are They?

The term night sight is mainly used when referring to traditional iron-type sights upgraded to accept small self-illuminating tritium-based lights or dots night. These are the most popular pistol night sights in use today.

As the name implies, pistol night sights are designed for nighttime or total darkness shooting needs. The sights were born out of a need to improve the traditional pistol’s sights for use specifically at night time.  

Night sights, in general, are available in a variety of brands and configurations. Three types are most relevant to civilian pistol users. These are:

  • Laser dot type that projects a dot onto a target, usually red. 
  • Reflex type or red dot type sights consist of a tiny lens that one looks through and has a red dot as a reference or aiming point. The dot is illuminated in the lens.   
  • Night sights, or traditional pistol sights, containing tritium-based illuminated dots as reference points. This option is by far the most popular pistol night sight today.    

How Do Night Sights On A Pistol Work?

Pistol night sights are high visibility sights that are visible at night or in dark spaces. 

The tritium-based sights look very similar to standard iron sights on a pistol. When shooting during the day, the sights are used as regular pistol sights. In dark areas or at night time, the improved dots of the sights come into their own. 

The traditional white dots of the pistol sights have been replaced with tiny self-illuminating lights that are invisible during the day but become very visible in the dark. 

The highly visible dots of the pistol night sights are clear reference points with which to aim. When aiming, place the dot of the front sights centrally between the two dots of the rear sight. At the same time, place the middle dot (front sight) onto your target. You’re now ready to engage your target.

Pistol Night Sights: How Do They Actually Work? 1

Are All Night Sights Tritium Powered?

The vast majority of pistol night sights use tritium-based sights. Other pistol night sight options do exist in the form of laser sights and red dot sights. Some gun owners may include fiber optic sights into this category, but I can’t entirely agree. Fiber sights require a light source to illuminate, which isn’t available at night. Fiber optic-based sights are excellent for use in the day and where sunlight shines onto the sight.

Laser pointer-type sights are great for night use as long as they’re sighted in correctly to the point of aim. The downside is that laser sights add bulk to the handgun, may give away the shooter’s position when turned on, and lastly, being powered by a battery could leave one in trouble when most needed due to a flat battery.

Red dot sights, or Reflex sights as they’re often called, are true day and night sights. Many different makes and sizes are available. All of which consists of a vertical lens or window, onto which a dot is projected. The dot is used as the reference point when aiming. 

When purchasing a red dot sight for night use, I’d recommend the battery-free, fiber optic, and tritium combination sight. The fiber component would create a clear dot during the day, and the Tritium light source would serve as the night sight. The downside of these sights is that they add bulk to your weapon, even though some models are very compact.  

How Long Do Night Sights Last?

The sight body is made from metal or composite material, robustly built, and should last a lifetime. The only component of the night sights that does deteriorate over time is the tritium lights or dots. 

The main active ingredient of most night sights is tritium. Tritium is a gas that is extremely rare and is a form of hydrogen. The tritium gas degenerates over several years, usually 20 to 25 years. Pistol night sight manufacturers have harnessed the unique properties of tritium’s regenerative process to create fluorescence or, in other words, the illumination in the dots of the night sights. 

Night sight manufacturers warrant the sights to be visible in the dark for between 10 to 15 years, depending on the brand. In reality, the tritium in the sights degenerates to about 50% of its original intensity over approximately twelve years, reducing the brightness of the dots on the sights.

Pistol Night Sights: How Do They Actually Work? 2

Are All Tritium-Based Pistol Night Sight Dots Green?

Night sights are available in several different options in terms of the colors of the illuminated dots. During the degeneration process of the tritium gas, electrons are given off that react with the fluorescent compound coating the inside of the glass tube. This reaction gives off light which is used to create the illuminated dots in the sights. 

The fluorescent coating used to coat the inside of the glass tubes determines the color of the light given off. It is available in various colors, including purple, blue, orange, yellow, red, or green. Green is the most popular color as the human eye detects it easily.  

Color combinations such as a red dot on the front sight and green dots on the rear sight are popular. By using two different colors, one can easily distinguish the sights, making the front sight the focal point. Some shooters even blank out the rear sights and only utilize an illuminated dot on the front sight. This option has merit as encounters at night are generally at close range and having only one dot to focus on the target makes for quick shooting.

Are Night Sights Illegal In The United States?

Night vision sights is a general term for all sighting devices that assist one to shoot accurately in dark conditions. These include the popular Trijicon-type sights, red dot sights, and various night vision optics. 

Night vision sights, including night vision scopes, are perfectly legal in the United States. Only California currently outlaws the use of sniper night vision scopes.

Do You Have To Charge Night Sights?

Pistol night sights do not need to be charged provided they are tritium based. The sights house small tubes which contain tritium and a fluorescent coating that react with each other giving off light. The intensity of the light is perfect for use in pistol night sights.

The chemical reaction that occurs within the sights can continue for years without any need to re-charge or, rather, replace the units. Typically, the Tritium sights are usable for about 12 years, at which stage the light-emitting units should be replaced, usually at a nominal fee. Interestingly, the dots on these sights glow all day and night, so they are always ready for use when needed. 

Some models of alternate night sights, such as the laser and reflex-type night sights, use a battery to power their systems. Ensuring the battery condition is always good is vitally important to ensure the sights work when you need them to. 

Pistol Night Sights: How Do They Actually Work? 3

Do You Need Night Sights With A Flashlight Or Gun Light?

Police officials have for decades survived violent confrontations without the need for night sights. However, most, if not all, would have had a torch. That being said, enough officials have been killed over the years during violent confrontations to make it mandatory for all new service pistols to be fitted with night sights as standard.

Ideally, you should have both pistol night sights and a flashlight or gun light. Of course, this depends on the situation you find yourself in. If your aim is to remain hidden, then obviously, shining a torch around won’t play in your favor.  You will then definitely need night sights if it is dark.

Should your primary aim be to identify your target clearly in a dark setting, you’ll need a flashlight or gun light before possibly engaging. In this scenario, I would still recommend having pistol night sights fitted as a torch can be dropped or lost, leaving you in the dark. Shooting blindly is definitely a situation you want to avoid. 

When firing a pistol at night using a torch, you’ll still require the use of sights to hit the desired target. Torches light up a target but do not assist the shooter in aiming accurately. Night sights will offer a distinct advantage as the sights will remain visible regardless of fluctuating lighting conditions. Remember that shot placement is paramount when engaging an attacker, so any advantage should be welcomed.   

Carry in a flashlight, either in hand or having a gun light fitted to your weapon, is cumbersome in both instances. Pistol night sights have been designed to be very compact, solid, and dependable. The chances of finding yourself in a hostile situation in total darkness is improbable. Attackers also need to see what they are doing to ply their trade, so low light conditions are more likely. In my opinion, this makes a flashlight of any sort unnecessary. 

Are Radioactive Pistol Night Sights Harmful?

Tritium gas is indeed radioactive and can be harmful to humans if breathed in, in a large enough quantity. Tritium cannot penetrate glass or human skin. Tritium is widely used in the world for GTLS (gaseous tritium light source) products. Illuminating items such as emergency exit signs, watch dials, and weapon sights, including pistol night sights.

Pistol night sight users need not be concerned about any harmful effects resulting from the use of the night sights. Although the tritium gas contained in night sights is radioactive, the amount used is so minuscule that in medical terms, no harm can come to you even if the glass tube is somehow ruptured

It’s reported that the total worldwide consumption of tritium, for all industries combined, is estimated at less than a pound in total per year. In total, astoundingly little.

Are Night Sights A Gimmick?

Night sights and specifically pistol night sights allow the user to see their sights clearly in the dark. As anyone who shoots a pistol or any weapon for that matter would know, accurate shot placement is only possible if you use your sights to aim. If you cannot see your sights, you’re effectively shooting blind. 

Night sights may be viewed as just another gimmick or gadget fitted to pistols purely to impress fellow shooters. It all comes down to if you have a use for night sights or not. Security personnel, police, and military, who work in all conditions, most definitely are advantaged by having pistols fitted with illuminated night sights. 

The average person who only uses his pistol for the odd range session may not see much merit in acquiring night sights. However, should you be carrying a weapon for self-defense daily, there’s no doubt that night sights fitted to your carry pistol will be invaluable should you need to use the weapon in low light or darkness.


Pistol night sights perform a vital role in low light or total darkness. Being able to see your sights quickly when needing to engage a target is critical in all instances except point-blank range. The tritium or three-dot configuration sights are by far the most popular due to their high visibility, compact size, and minimal maintenance required to ensure trouble-free operation for years on end. 



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