Fiber

Fiber Optic is a transparent polymer fiber capable of collecting ambient light (sunlight, sky, artificial lighting) and transmitting it into a single point. At the end of the fiber, the gathered light forms a bright colored dot (usually red or green), which serves as an aiming point in sights and riflescopes. Fiber-optic technology originated in the telecommunications field in the 1960s–70s, but its adoption in firearm sights appeared later, around the 1980s. Key pioneers include companies such as TruGlo and HiViz, among the first to produce fiber-optic pistol and rifle sights. A major contributor is also Trijicon, which combines tritium and fiber optics in ACOG and other optics. We also cover the Fiber Reticle technology in detail in our article.

How does fiber optic work in riflescopes (e.g., ED Fiber in Vector Optics)?

In riflescopes labeled ED Fiber, the fiber optic is positioned to collect light from the environment and channel it into the center of the reticle. This creates a bright dot or aiming point that remains visible even without electronic illumination. The more ambient light, the brighter the dot shines. The advantage is that no battery is required, so there is no risk of running out of power, and the optic remains simple and highly reliable. The ED (Extra-low Dispersion) designation indicates the use of glass with very low light dispersion, which reduces chromatic aberration and provides a clear, high-contrast image. Combined with fiber optic, you get a riflescope with a sharp image and a bright daytime aiming point without electronics.

Where is fiber optic used?

Riflescopes:
Models with a fiber-optic aiming point (e.g., selected Vector Optics ED Fiber riflescopes, various hunting and tactical optics).
Hybrid sights:
For example, Trijicon ACOG – a combination of tritium and fiber optics for daytime and nighttime aiming dot visibility.
Pistol sights:
Fiber-optic front and rear sights from brands such as TruGlo, HiViz, and also CZ, Glock, or SIG on sport and tactical models. In airsoft, similar sights appear on pistols intended for fast dynamic shooting.

Advantages of fiber optic

No battery: The dot glows thanks to ambient light, with no need for electronic illumination.
Fast aiming: The bright dot makes quick target acquisition easier – ideal for dynamic shooting, hunting, and airsoft.
High reliability: No electronics, minimal risk of failure.
Low weight: The fiber is extremely lightweight and does not burden the optic.

Disadvantages of fiber optic

Reduced visibility in darkness: Dependent on ambient light – in complete darkness, without another source (e.g., tritium or LED), the dot may be faint.
Sensitivity of cheaper sights: On low-quality copies, the fiber may be more fragile or poorly fitted.