The Brock string was named after Frederick Brock, who developed it as a tool to help him correct his own vision problem.
 
The idea that the eye can be trained to improve visual cognitive strength is a part of a new growing field titled “visual neurocognitive motor training.” 
 
The brock string is one of the many tools used to improve visual skills such as depth perception, peripheral visual field awareness, hand-eye coordination, and even balance.

The brock string consists of a 10-15 feet white flexible string with colored wooden beads that move to different spots on the line. To use the brock string, you simply hold up one end to your nose and look down at the colored bead called out. This exercise fortifies the relationship between the eyes and strengthens the ocular muscle balance. When athletes repeat these exercises, they can quicken the pace and efficiency of the electrical impulses that the eye sends to the brain. 
 
The more you practice, the more efficient those electrical signals become. Vision exercises like this can make all the difference in your performance, and it is essential to keep up to date with them!
 
When using the brock string, one end is held at the tip of the nose, while the other is tied to a fixed point—often our patients will use a doorknob. Three beads on the string are placed at different distances, and the patient must focus on each of the beads. It helps develop better binocular vision.
 
 
One of the most important pieces of equipment for vision exercises when working on convergence is the brock string. It offers instant feedback to the participant if their eyes are working together to focus on an object at various distances.
 
 
This is the 20 ft version