At night, the light is too dark, which reduces the stimulation to the eyes and makes it impossible to see clearly; There is another kind of people who can't see clearly at night. This is a disease called night blindness. The former is the case of ordinary people, and the solution can strengthen lighting; You can also use a night vision device, which is an instrument made of sensitive elements that can feel infrared rays. Although there is little visible light at night, as long as the temperature exceeds absolute zero, it will emit infrared rays. Therefore, components that can feel infrared rays can also "see" things at night. Of course, its clarity and resolution are still very different from those seen during the day. Night blindness belongs to the latter, mainly because of the lack of vitamin A in the body. Eat more foods or drugs containing vitamin A, such as animal liver and carrots. Note that vitamin A is fat-soluble and needs oil to be dissolved and absorbed. So it is effective to eat oil at the same time when eating.