Back in the 1990s, thermal sights for infantry weapons were unheard of. But now the second generation of these sights have been in combat for three years, and new models keep arriving with improvements in range, detail, zoom and reliability. Some of the latest models can be clipped on day sights, without requiring zeroing the combined sight all over again.
It was only four years ago that the second generation of thermal weapons sights began reaching the troops. The new sights revolutionized the way troops fight at night, since “thermals” sense heat, and are effective anywhere (the old night sights depended on amplifying available light). Thermal sights are particularly popular because they also identify any warm machinery, at long distance, by detecting heat, and they can be used in caves (and other places that lack any light to amplify) as well as in situations like sandstorms and fog.