In the middle of the retina there is a small pit, the fovea , with which we see sharply. When a person with normal vision looks straight forward without moving the eyes, he sees also on both sides. The area visible at once, without moving the eyes, is called visual field . Visual pathways from the eyes to the visual cortex. Note that there are also connections to the central parts of the brain.
Visual information coming from both eyes is fused in the visual cortex in the back of the brain.
On both sides of this central, binocular field there are half moon formed parts of visual field that are seen by only one eye. A. Visual field of both eyes. We use our peripheral or side vision when moving around. The most central part of the visual field is used in sustained near work, e.g., reading. When the visual field is measured with the clinical instruments these instruments measure what the weakest light is that the eye still can see in different parts of the visual field.