Strabismus, Binocular Vision, and Adaptations

Strabismus or squint is one of the underlying pathologies that are, if presented in early childhood, likely to result in amblyopia. It is characterized by the deviation of the two eyes, which is problematic not only cosmetically, but it also profoundly affects healthy vision. More specifically, strabismus has a significant impact on a person’s binocular vision.

What is Strabismus?

Strabismus , also known as “crossed eyes” or “squint,” is a condition in which the eyes do not align properly, causing them to point in different directions. It can occur due to various factors, such as muscular imbalances, nerve issues, or even genetics. Strabismus can manifest as esotropia (inward turning of one or both eyes), exotropia (outward turning of one or both eyes), hypertropia (upward turning of one or both eyes), or hypotropia (downward turning of one or both eyes).

The Impact of Binocular Vision

Binocular vision refers to the ability of both eyes to work together as a team, allowing us to perceive depth, judge distances, and have a clear, three-dimensional view of our surroundings. Strabismus disrupts this coordination, leading to challenges in achieving binocular fusion, which is the process of merging the visual inputs from both eyes into a single, unified image.

Optimal Binocular Vision: Depth Perception and Adaptability

Humans have our two eyes positioned in front of our skulls, which enables us to have a very good binocular vision and the perception of depth. This allows us to drive, play sports, or walk without too much effort.

When our two eyes are properly aligned, our retinas will simultaneously send balanced signals from each eye and the brain will be able to calculate and judge the distance of objects in space effortlessly with great precision.

If, for whatever reason, our two eyes become misaligned the latter will become impossible. Our brain is then left with two options, neither of which are good. The human brain is remarkably adaptable, and when faced with visual challenges like strabismus, it can employ ingenious mechanisms to mitigate the impact.

Our Brain Compensates for Eye Misalignment

The first compensation is diplopia, or double vision, which would result in doubling everything we see—pretty annoying, right? The second one, though, simply shuts down the signals coming from the deviating eye, resulting in the loss of binocularity and the perception of depth.

In young children, due to high brain plasticity, the latter is usually what happens. Short-term, this is better option of the two, as the kids thus very rarely experience bothersome double vision, but long-term, it can lead to deep amblyopia with impaired visual acuity of the deviating eye as well as decreased ability to develop healthy binocular vision and the perception of depth.

Restoring Binocular Function is just as important as Restoring Visual Acuity

The goal of strabismus and amblyopia treatment is then to restore the visual acuity of the deviating eye as well as to establish healthy binocular vision without the impaired perception of depth.

It is usually achieved so with a combination of correct refractive correction, patching, sometimes surgery, and vision training such as AmblyoPlay.

Conclusion

Strabismus poses unique challenges to individuals striving for binocular vision. However, the remarkable adaptations and compensatory mechanisms that the brain employs demonstrate the incredible resilience and plasticity of our visual system. Through techniques like suppression, amblyopia correction, head tilting, reliance on monocular cues, and multisensory integration, individuals with strabismus find ways to navigate their visual world with ingenuity and adaptability.

Frequently Asked Questions