Fig. 1. Center: A graphic representation of Traquair's island of vision. The island contour represents the field of vision, where the higher a loci is situated on the island, the more sensitive the point on the corresponding visual field at points corresponding to the peak of the island (foveal fixation). Top: The curves (isopters) labeled I4, II4, and III4 on the island of vision connect corresponding areas of equal threshold sensitivity and are plotted (kinetic perimetry). Bottom: The shaded region on the island delineates the area of the visual field to be tested statically. The three points within the shaded area on the surface of the island of vision have a specific height and therefore a threshold value. These values are recorded as points with specific threshold sensitivity values (dB).