they did not have lens caps on and the pic was not digitally altered. The lenses of those binoculars are reflective, nightvision binoculars with a honeycomb type lens.
Same technology in other pics:
"Computer-aided grinding and magnetorheological finishing are automating the manufacturing process for high-precision lenses such as those used in military and medical applications
The Center for Optics Manufacturing (COM) in Rochester, N.Y.--a consortium comprising the U.S. government (primarily the Army), academia, and industry--has been developing practical, economical ways to automate high-precision lens making.
Night-vision binoculars use high-precision lenses made of germanium, which transmits infrared light well but is opaque to visible light"