Electron-optical night vision devices of I+ generation

I+

— modification of the first generation image intensifier tube (see the relevant paragraph), which introduced a number of improvements in the image; in particular, the resolution across the entire field has become uniform, and geometric distortions have become almost imperceptible. However the price for these improvements was bulkiness and a significantly increased cost compared to generation I image intensifier tubes, which is why this option did not receive much popularity.