An apparatus for improving a visual function, the apparatus having a first display element for displaying at least one moving grid consisting of grid elements at least one portable closure element for the occlusion of at least one eye a portable eye tracking device for measuring at least one characteristic value of a non-occluded eye a first control unit having a first communication interface to the eye tracking device and a second communication interface to the at least one closure element and a second control unit connected to the display element, with a third communication interface to the first control unit. The second control unit is adapted to provide a display to a non-occluded eye of the moving grids on the first display element controlled on the basis of the characteristic values measured by the eye tracking device.