Clear Vision Does Not Mean Your Vision is Comfortable
To have comfortable vision, your two eyes need to work together as a team binocularly. Your brain receives images from both your eyes at the same time, and combines them to create one single image. Binocular vision dysfunction (BVD) occurs when these two separate images from the two eyes cannot be successfully merged into one image in the brain. This usually results in headaches, diziness and eyestrain. You may also experience double vision if your visual system breaks down.
There are several types of binocular vision disorders:
- Horizontal eye misalignments – convergence insufficiency, convergence excess, divergence insufficiency, divergence excess
- Vertical eye misalignment – vertical heterophoria
- It is also possible to have a torsional misalignment between the 2 eyes
- Strabismus – completely “turned” eye
- Amblyopia – “lazy” eye
Problems with binocular vision occur more than you think. Many times, a binocular vision disorder is overlooked in an eye examination. They often go undiagnosed because you can pass a typical eye chart test or be told that “everything is normal”, that you have “20/20 vision”, yet still have problems even though you have clear vision.
This leads to frustration among adult patients and, in the case of children, parents wondering why they struggle in school.
It is common for people with BVD to have been previously diagnosed with a number of conditions including ADD/ADHD, agoraphobia, anxiety disorders, vertigo, perceptual diziness, vestibular migraine, sinus problems, and reading/ learning difficulties.
Common symptoms associated with binocular vision disorders include
- Eyestrain or headaches
- Double vision
- Closing one eye
- Blurry vision after near work or computer work
- Avoiding near work
- Trouble concentrating or feeling tired
- Losing place or skipping lines while reading
- Dizziness and nausea
- Feeling carsick easily
- Anxiety in open spaces or while driving
If untreated, problems can lead to more serious eye problems such as lazy eye (amblyopia) or even an eye turn (strabismus).
If binocular vision problems are left untreated, suppression can result. Suppression of vision means that the brain will actively shut off one eye, causing loss of binocular (two-eyed) vision and depth perception.