Why do people have driving difficulty at night?

https://www.aarp.org/auto/driver-safety/driving-in-the-dark.html?cmp=EMC-DSM-NLC-OTH-WBLTR-1532702-1915305-7856314-NA-12152023-Webletter-MS3-NA-NA-S08A-Auto&encparam=LWgxHqFTeD3ZOS4E0jqf4hencYDHMg6eRi2tRfy9reE%3d