Brock String

General benefits

Usually, this practice is used to develop the binocular vision. It can be used as warm-up exercise or main exercise. It also help at fixation.
It was invented by Frederick W. Brock.

What’s our purpose with it?

Our purpose is to teach our eyes to move synchronously and to see simultaneously with them.

How is it look like and what is required to it?

Typically, it is a 110 cm long, white string with 3 beads (in different colors).

Brock String

Brock String

(This string can be shorter (min. 30 cm) or longer and it can have more or less beads eg.: 60 cm with 2 beads or 3 m with 5 beads.)

We get more feedbacks from the tool if we use two color glasses during the practice because with it we can see the string in two different colors so it is easier to separate the two lines.



Usage guide:

  1. Tie one end of the sring at a fix point eg.: doorknob.
  2. Fix up the beads equal distance from each other (listen, don’t let less 30 cm destance between the beads).
  3. Hold strongly the other end of the cord up to the bridge of your nose so that the cord is stretched tight between your nose and the doorknob.
  4. Try to focus for the first bead in 5 secons then for the others. Do it backwars too. Repeat it 10 more times.

If your fixation of the bead is accurate, the two strings should appear to meet exactly at the bead forming an “X”.

What next?


Brock string instructions

Brock String


3 thoughts on “Brock String

  1. Kevin

    Since I only can view out of one eye at a time right now. My right eye being amblyopic, do I have to try and use both eyes during this exercise or use the eye I view out of. Which would be my left?


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