This is the way sensor cells in the human eye look under a microscope. There is a much higher concentration of cells in the center of the eye. These cells become more spaced out the further away they get from the middle. This is why our peripheral vision is blurry and cannot see detail outside of the parameter we are looking at directly. Every cell receives visual input much like camera sensors. The closer the cells are together, the sharper the image becomes. The more space between the cells the blurrier the image becomes.
Because of the format of a canvas, paintings become cropped, which results in unnatural and abrupt interruption to eye flow and contradicts how we perceive the world. Therefore, we must rely on artistic techniques to offset this.
In the eye’s peripheral vision: