Foveal

The foveal system of the human eye is the only part of the retina that permits 100% visual acuity. The line of sight is a virtual line connecting the fovea with a fixation point in the outside world. The foveal system of the human eye is the only part of the retina that permits 100% visual acuity. The line of sight is a virtual line connecting the fovea with a fixation point in the outside world. The discovery of the line-of-sight is attributed to Leonardo da Vinci. His main experimental finding was that there is a distinct and clear vision only at the line-of-sight, the optical line that ends at the fovea. Although he did not use these words literally, he is the father of the modern distinction between foveal vision (a more precise term for central vision) and peripheral vision.