Peripheral vision

Peripheral vision is the part of the field of vision that is outside the central vision, i.e. the part that you see sharply. Peripheral vision is 98–99% of the field of vision that we cannot perceive as clearly as central vision. This is exacerbated when we are tired or under the influence of alcohol. We can detect things with peripheral vision, but must use direct vision to be able to clearly see what it is. Imagine that you are focusing on a point (live vision). Everything else that you don't have in focus is peripheral vision and it's rarely as sharp as your direct vision.