What is BVD?

Binocular Vision Dysfunction describes any condition where the two eyes have difficulty working together as a team to create one clear image. This results in image misalignment. The body attempts to correct this vision misalignment by overusing and severely straining the eye muscles.

In people with normal binocular vision, their eyes work in tandem, perfectly in sync at all times, to send one clear, focused picture to the brain. However, in people with Binocular Vision Dysfunction, the eyes do not work together and are not perfectly synchronized - this makes it difficult for them to see one clear image.

When the misalignment is severe, it causes double imagery or double vision. However, in most cases, the misalignment is very subtle, historically making it difficult to identify. Even when the misalignment is small and physically unnoticeable, the symptoms can be debilitating.

Causes of BVD

BVD can be caused as a result of several different factors. Some people experience BVD due to facial asymmetry, where one eye is physically higher than the other. It can also be caused by a nerve or eye muscle abnormality, which is something many people are born with. As people with these abnormalities get older, the eye muscles become even more strained from trying to constantly realign the image they are sending to the brain, which results in the uncomfortable symptoms of BVD.

BVD can also develop as a result of a stroke, brain injury, or similar neurological disorder. It can manifest at any time, with symptoms usually developing around 40-years of age.

Symptoms of BVD

The symptoms of BVD can interfere with a patient’s ability to function, including basic tasks such as driving a car or reading. Essentially, BVD can severely negatively impact their quality of life. Patients with BVD experience the following symptoms:

• Headaches

• Neck ache/head tilt

• Double vision

• Sensitivity to light/glare

• Reading difficulties

• Anxiety

• Motion sickness

• Dizziness

• Balance Problems

• Fatigue with reading

• Shadowed/overlapping/blurred vision

• Feeling overwhelmed in crowds/large spaces

• Skipping lines/losing your place while reading

• Closing/covering an eye to make it easier to see