Compared with the first and second generation low-light night vision devices, the prominent symbol of the third-generation low-light night vision devices is the third-generation image intensifier as the core component. This image intensifier replaces the previously described polybasic photocathode with some kind of photocathode with negative solar electron affinity. This replacement has changed the performance of the image intensifier and even the performance of the third-generation low-light night vision device. In order to give full play to the performance advantages of the third-generation image intensifier, the matching optical system also performs Several new ideas have been introduced, such as the use of aspherical surfaces, the introduction of optical plastic lens components that are easy to manufacture and replace, and the application of optical full-system lenses.