The bifocal was famously invented by Benjamin Franklin in 1784. This invention was an efficient way of assisting those who need different levels of vision correction for different focal ranges. For example, those who need glasses to see things far away, but not close up.
One of the first challenges that almost all newborns face in this world is that they somehow have to make sense of this brand new visual world with nothing much more than blurry blobs of contrast to go by.
The normal field of vision is around 170 degrees, and of that, about 100 degrees are peripheral vision. To understand just how narrow your area of clear focus is, try fixing your eyes on THIS WORD and see how much of this page you’re able to read.