By Andre’ M. Dall’au
“Sights can be now effectively and accurately used in low-light conditions by two primary methods, by addition of battery-free visible light sources using fiber optic or tritium sources to align the shooter’s eye with the target.”
“The best of both illumination technologies in one sight is not a wish, but now a reality as there are several options from optics and sighting system manufacturers like Meprolight.”
To accurately place a projectile where a shooter wants, the simple, physical fact is both the target and the sights needs to be clearly visible.
If you can’t see one or the other, then it’s a wasted or unsafe shot. There have been whole markets established to manufacture products that illuminate targets including lights of all kinds both on and off the firearm as well as a separate and very useful subset of training for shooters to engage in low-light conditions (that every defensive shooter should attend.)
The other needed requirement for accurate shooting is being able to see and align your sights. That has been accomplished in a variety of solutions from everything from optics like a red dot, reflex, holographic or powered optics as well as ways to illuminate open sights.
Open sights, also called iron sights, and even optical sights like red dot and telescopic sights can be now effectively and accurately used in low-light conditions by two primary methods, by addition of battery-free visible light reticles using fiber optic or tritium sources to align the shooter’s eye with the target.
What are Tritium Sights?
Shooters appreciate the use of glowing tritium sights to provide a clear target solution. But how does that incredible technology work? Tritium sights contain a small vial of gaseous radioactive tritium that emits charged particles interacting with an internal coating of phosphor causing a reaction that produces radioluminescence and phosphorescence the shooter sees as a glowing dot. The gaseous tritium is a radioactive isotope of hydrogen that constantly decays through the emission of beta particles and requires no additional power source but as a byproduct, produces a low-intensity light that won't degrade human night vision. The small vials of tritium with a phosphor coating are called a gaseous tritium light source (GTLS), or since the tritium undergoes energetic beta decay, they are also referred to as a “beta light.”
Being a radioactive beta decay source, every GTLS starts to diminish in intensity from the moment of encapsulation by a process called a half-life which is the amount of time the source takes to naturally decay by half. The half-life of tritium is 12.32 years meaning that in about ten years the tritium sight has lost about half of its “glow” (still visible though) and in twenty years has lost most of its potency. In addition, over that same time, the degradation of the phosphor will also cause the brightness of a tritium tube to decrease.
Tritium vs Fiber Optic Sights: How They Work and What You Need to Know
Tritium sights provide a constant, non-adjustable glow that remains visible in total darkness but can appear less bright in direct sunlight. Unlike fiber optic sights, tritium night sights work perfectly in complete blackout conditions. Tritium uses a phosphor compound that emits light in various colors—green, red, blue, yellow, purple, orange, and white—depending on its chemical makeup. Green tritium sights are the brightest due to the way the human eye perceives color, while red glows less intensely.
Many shooters ask if multiple radioactive sources on a pistol pose health risks. Tritium emits low-energy beta radiation, which is largely contained within the sealed vial and cannot penetrate the skin. The main risk arises if a vial breaks—avoid inhaling near broken tritium vials and ventilate enclosed spaces.
On the other hand, fiber optic sights use optical fibers that absorb ambient light and channel it through the fiber via total internal reflection. This concentrates light into a bright dot visible to the shooter. Fiber optics rely on available light and don’t glow in total darkness. Their acceptance cone guides light for a bright, clear sight.
In summary, tritium sights excel in darkness with self-illumination, while fiber optic sights offer bright, passive illumination in daylight. Understanding these differences helps you choose the best sight for your shooting needs.
What are the Advantages and Disadvantages of Fiber Optic Sights?
Fiber Optic sights have an illuminated dot or reticle completely dependent on the available light. In total darkness, fiber optic sights show no visible glow. In bright light, their brightness can obscure small targets, causing some to cover fibers with tape. Fiber optic sights adjust naturally to changing light, preventing sudden brightness or dimness when moving between environments.
Powered red dots can glare indoors after bright sunlight. Fiber optic sights don’t lose brightness over time and cost less than tritium sights. Tritium and Fiber Optic sights are excellent for their strengths. Tritium provides a constant glow until it fades, while fiber optic sights are cheaper and brighter in ambient light. I use both and work around their weaknesses but there’s an option better than choosing just
Fiber optic vs. Tritium Sights: Which one is Better?
Choosing between fiber optic and tritium sights depends on what you need as a shooter. If budget matters, fiber optic sights are an affordable, reliable choice. For use in complete darkness, tritium sights provide superior, self-powered illumination. But if you want a sight that maintains brightness without fading over time, fiber optics are ideal.
What’s better than choosing one? Combining both technologies! Leading brands like Meprolight® combine fiber optic and tritium illumination in sights, offering shooters the best of both.
Meprolight® uses patented fiber optic technology paired with tritium in products like the Meprolight.com (red dot) sight for rifles and the Mepro FT Bullseye™, a micro rear sight that requires no batteries. These sights perform perfectly in any lighting, day or night.
Recognizing this innovation, SIG SAUER equips its P365 and P938 micro-compact pistols with the factory-installed Meprolight FT Bullseye sight. This low-profile, flush-mounted sight offers fast target acquisition with its illuminated bullseye reticle, compatible with most standard holsters. Shooters can also upgrade their pistols by replacing front or rear sights with Meprolight’s red or green bullseye reticles.
I’ve used the Meprolight.com on my Glock 43 for years—shooters love its accuracy and clear sight picture. Plus, it fits perfectly in my existing pancake holster. Meprolight guarantees tritium luminance for up to 12 years.
For more details or to find a dealer, visit Meprolight.com
