How does Night Vision work?
Bushnell Night Vision products collect and amplify existing light through the objective lens which is then focused on the image intensifier. Inside the intensifier, a photocathode is "excited" by the light and converts the photon energy in to electrons. These electrons accelerate across an electrostatic field inside the intensifier and strike a phosphor screen (like a green monochrome TV screen) which emits an image that you can see. It is the acceleration of electrons, which provides gain and enhances the image.