It takes about 5 to 10 minutes to fully adapt from bright lights inside to complete darkness outside. Human vision has the incredible range of light, thus we can see in very birght sunlight, and we can also see in nearly total darness. The reason why we can see from bright lights to dark lights totally depend on two cells of eyes. The first one is called rod cells that is located in the retina, which can preceive black and white images and work best in low light. The other one is rhodopsin that is a chemical found in the rods and is the key to night vision. Due to it can absorb photons and preceive light.
