Brock string



A Brock string is an instrument used in vision therapy. It consists of a white string of approximately 10 feet in length with three small wooden beads of different colors.

The Brock string is commonly employed during treatment of convergence insufficiency and other anomalies of binocular vision. It used to develop skills of convergence as well as to disrupt suppression of one of the eyes.

During therapy, the one end of the Brock string is held on the tip of the nose while the other is tied to a fixed point. The three beads are spaced out a various distances. The patient is asked to focus on one of the beads, while noting the visual input of each eye and sensation of covergence. Techniques may be made more difficult by bringing the beads closer to the nose and by employing lenses and prisms.

Reference

 * Scheiman, Mitchell and Wick, Bruce. Clinical Management of Binocular Vision. Lippincott, New York. 1994. pgs 188-192.