Basically, you have two types of vision: Central and Peripheral. Central vision is the vision you have when you look at something directly and see the details. Peripheral vision is the rest of the visual field that is visible, but that you are not looking directly at.

https://www.blog.theteamw.com/2010/01/23/100-things-you-should-know-about-people-22-peripheral-vison-keeping-you-alive-or-channel-surfing/