Participants: 68 primary school students, 44 boys and 24 GirlsIn this study, visual pursuit test (LVT) S2: short time version (40 graphs) is used to measure the visual perception of the centralized target. There are 40 test questions in total. Under a relatively complex graphic environment, the test method walks from the starting point to the end point in the way of the track along the line, and tests the visual direction ability. The subject follows the starting point indicated by the red arrow on the line of the graph, and the end point is indicated by the number to judge the position where the end point is No. 1-9.