Our eyes are an inch or two apart, each with own lens and retina to process information. However, when we look at a scene, we see one image and not two as one would expect. Why is this so? It’s because of what we call ‘ binocular vision’; the innate ability of the brain to coordinate with the eyes, merging two different images from our two eyes to become one image. It enables us to see better, comfortably, judge depth and distances in a better way.
What is Binocular Vision Capability and Why is it Important?
Binocular vision is important for the following reasons:
It allows you to perceive distances and depths correctly so you can walk without tripping, pick things from the ground easily, and walk around without bumping into things. It makes manoeuvering through crowds possible, reading comfortable, and driving safe a safe activity. Without binocular vision, one’s life would greatly be affected.
Not every person has this ability to process information from both eyes to a smooth, single image. Sometimes, disorders occur that cause a malfunction, with the affected person experiencing double vision. The resulting vision is known as monocular vision and can be uncomfortable and stressful to endure.
What are The Causes of Binocular Vision Disorders?
Binocular vision disorders, (BVDs), are mostly inherited. A child could be born with misaligned eyes which later cause BVD. Another cause is some neurological diseases that cause muscles to malfunction. Old age, too, is a known cause for BVD as a result of eye muscle degeneration. Injuries to the head or head trauma can make someone to develop BVD later in life.
Binocular vision disorders include:
- The eyes failing to focus simultaneously in the same direction
- The ‘lazy eye’, a disorder quite common in children and infants. It usually affects one eye when the brain prefers one eye over the other
- The brain failing to process images from both eyes
- Convergence insufficiency or when the eyes fail to turn towards each other when viewing objects at close range
Other binocular vision impairments are cataracts, nearsightedness, and farsightedness
What are The Symptoms Binocular Vision Disorders?
Symptoms vary according to cause. They’re mainly caused by the strain put on the eyes as the brain tries to move the muscles of the eyes to correct the images coming in. The symptoms range from mild to severe depending on the level of misalignment of the eyes, or the degree of eye muscle damage. They include:
- Double vision
- Headaches varying from mild to severe
- Unsteady gait as a result of misjudging distances and depths
- Feelings of lightheadedness
- Problems with the sinuses with bouts of pain in the nose and the jaw areas
- Increased sensitivity to light
- Problems reading from a book or a screen, with text occasionally overlapping
- Motion sickness and general feelings of nausea
- Feelings of discomfort in the upper body as a result of having to twist it trying to focus the eyes. Or there could be lines of the forehead brought about by frequent lowering if he head trying to focus the image perceived
- Anxiety and phobia for crowds as a result of seeing multiple images of people which causes loss of direction and dizziness
- Walking into other peoples lanes unintentionally while taking a normal walk
- Perceived motion of objects from the sides of the eyes when none are moving
- Reading text more than once to understand it or losing track of place when reading, forcing one to use a finger to navigate
There are many symptoms of binocular vision disorders, some common and others not too common. Because some of the symptoms may be unrelated BVDs, it’s always advisable to seek the advice of an eye specialist for a proper diagnosis. Only after tests can the doctor tell if someone has a problem with their binocular vision ability.
Treatment involves giving corrective glasses, so the eye muscles don’t strain anymore to correct an image. Usually, patients show improvement less than an hour after wearing the prescribed spectacles with the major symptoms disappearing altogether.
With the stress the loss of binocular vision brings to one’s life, you should consider getting medical help at the slightest onset of symptoms. Symptoms can at times take long to manifest and visiting an ophthalmologist on a yearly basis to have your vision tested would help.