The Brock String is a powerful vision therapy tool that is very frequently used during the treatment of different forms of convergence problems, such as Convergence Insufficiency, as well as for patients with amblyopia and strabismus. Children with reading problems or who are slow readers often have problems with convergence. While relatively simple in design (a Brock string is made of a rope with 4 different colored beads), it is a very powerful tool in vision therapy. It helps to both diagnose and determine different binocular dysfunctions, as well as a treatment solution that helps strengthen patients’ binocular function and eye collaboration. Despite being primarily associated with binocular vision, we can also help strengthen fixation under binocular conditions.