Sight (device)

A sight or sighting device is any device used to assist in precise visual alignment (i.e. aiming) of weapons, surveying instruments, aircraft equipment,^[1][2] optical illumination equipment or larger optical instruments with the intended target. Sights can be a simple set or system of physical markers that serve as visual references for directly aligning the user's line of sight with the target (such as iron sights on firearms),^[3] or optical instruments that provide an optically enhanced—often magnified—target image aligned in the same focus with an aiming point (e.g. telescopic, reflector and holographic sights). There are also sights that actively project an illuminated point of aim (a.k.a. "hot spot") onto the target itself so it can be observed by anyone with a direct view, such as laser sights and infrared illuminators on some night vision devices,^{[citation needed]} as well as augmented or even virtual reality-enabled digital cameras ("smart scopes") with software algorithms that produce digitally enhanced target images.