Healthy eyes have a natural ability to converge on an object being viewed in such a way that the image is centered in the macula. You may have noticed that when viewing close objects, your eyes naturally converge, while when viewing distant objects, your eyes align nearly parallel to each other. In both cases, our vision has an extraordinary ability to maintain close and distant objects in sharp focus. Of course, this applies only to healthy vision without convergence disorders.

Proper convergence allows for a deep and accurate perception of depth in the 3D world. The brain automatically combines images from the right and left eyes into a single three-dimensional whole. This ability helps us, among other things, estimate the distance of objects relative to us. Untreated convergence problems can lead to the development of strabismus, either convergent or divergent.

You can find more information about this condition here

For this exercise, we will use convergence charts. The main goal is to create a virtual image, allowing each eye to work separately, strengthening coordination between the eyes and improving the functionality of eye convergence.

1. Use any of the convergence charts and place it about 50-70 cm (19-28 inches) away from you at eye level. Then, extend your arm with a straight thumb (or pen) halfway between you and the chart and focus on it while observing the shapes on the chart.
2. You should see a total of 4 shape images on the chart. While maintaining convergent vision on the thumb, try to bring it closer or further away so that the 2 inner images merge into one, and you see a total of 3 images (2 are real, and one is virtual). As time goes on and you gain experience, you will be able to see 3 images immediately (even without using your thumb).

1. Use any of the divergence charts and place it about 40-50 cm (16-20 inches) away from you.
2. Look between the stars or simply over the top of the chart and gaze into the distance. It may be helpful to look at a distant object several meters away. When you succeed, you should see a third (shadow) image, e.g., a star in the middle of the two on the chart. Adjust the distance of the chart from yourself so that the third image is more clearly visible, exactly in the middle of the other two.
3. Then look at the next row of stars. This will require changing your gaze to a slightly shorter distance than the first row to see three stars again. Look at each of their details. Notice that the white circle comes from a different side this time. If one of your eyes is weaker, you may have difficulty seeing the white circle in one or both rows of stars. If the muscles of such an eye are also weakened, the central image will converge to one side. If you have a problem with this, take a break for a few seconds or blink several times.
4. Continue the exercise with the following rows down and then back up again.
5. You can also perform the star exercise in convergent vision mode by moving the chart slightly further away and crossing your eyes in front of the chart.

1. Choose a distant object, then hold your thumb at the height of the object you're looking at and focus on it. You should see two images of the distant object.
2. While maintaining convergent vision on your thumb, try to observe the left image of the object and notice as many details as possible. Then return to your thumb and repeat this procedure for the right image of the object. If you have a problem with a "lazy eye", you'll notice that one of the object's images (the one seen by the weaker eye) is less distinct. Spend more time working with this eye.
3. Now reverse the process. Focus on the distant object. You should see two thumbs. Repeat the process from step two, focusing on the left and right images of your thumb.

Strabismus (squint) is an eye condition characterized by weakened eye muscles, causing a change in the angle of one eye relative to the other. The result of strabismus is a disruption of stereoscopic vision. You can find more information about this condition here

When training the eye with strabismus, we need to correct the "alignment" of the muscles, that is, try to influence the coordination of the eyes and bring it to a natural balance. Strabismus treatment with vision training can be divided into 2 phases:

1. Strengthening eye coordination through convergence exercises and practicing eye muscle flexibility so that the strabismic eye begins to cooperate with the other eye. For this purpose, we use a string as a reference point. The aim is to see a phantom cross, which will become visible when the correct alignment of both eyes and their convergence on the object we want to see is achieved.
2. The second stage is training the deviating eye and its main defect (e.g. nearsightedness). This is because the eye affected by strabismus usually has a greater defect than the other eye. Equalizing sharpness between the eyes will therefore result in a greater balance between the eyes and thus complete healing of strabismus

This exercise was developed by Clara Hackett, and its aim is to relax the eyes and make them work together.

1. Stand with your back to the mirror in a slight straddle so that your feet are about shoulder-width apart.
2. Cover your healthy eye (let's assume it's the right one) with your hand and look straight ahead with your other eye.