Fossa fovea
The fovea is a small depression in the center of the retina of the eye. This area contains only cones and provides the greatest visual acuity.
Cones are photoreceptor cells in the retina that are responsible for color vision in bright light. In the central fovea their density is especially high. That is why the fovea is responsible for visual acuity - the ability to distinguish small details.
Due to the high concentration of cones, the fovea provides the clearest image of the part of the visual field on which the gaze falls. The image of objects falling on the peripheral areas of the retina is perceived worse.
Thus, the fovea plays a key role in ensuring human visual acuity.