Binocular Vision Disorders

What causes BVD?

Eye misalignment can be a result of facial asymmetry (where one eye is higher than the other), nerve or eye muscle abnormality (a common condition many people are born with), or it can develop as a result of concussion, head injury, stroke or a similar neurological disorder.

Concussions or head injuries, such as car accidents or falling, may result in eye muscle or nerve damage causing double vision. Sometimes the symptoms go away on their own, but many times they do not.

What is the NeuroVisual Exam for BVD?

Dr. Beth Knighton has trained in the cutting-edge work of diagnosing and treating Binocular Vision Dysfunction. A comprehensive NeuroVisual exam is designed to assess your entire visual and physical system, including:

• Eye movement
• Eye teaming and tracking
• Eye focusing
• Binocular Fusion
• Balance and gait stability
• Posture and neck alignment
• Visual-spatial awareness
• Depth Perception

The initial NeuroVisual Evaluation is usually scheduled for about 2 hours, to give time for patient history, vision testing and wearing “trial prescription” eyeglass lenses. Patients are usually scheduled for a 1-hour Progress Assessment a few months later to re- evaluate the symptoms and often revise the eyeglass prescription.

How is BVD treated with prism glasses?

If a misalignment is diagnosed during the NeuroVisual evaluation, the doctor will prescribe prism glasses. Prism lenses compensate for eye misalignment by redirecting light rays so both eyes see the same image. Prism is combined with your regular prescription and doesn’t look any different from a normal pair of glasses, but prism can significantly relieve BVD symptoms.

Prism is measured and prescribed in prism diopters (D). Prism also has a direction: horizontal (in or out) and vertical (up or down). Historically, prism was prescribed in whole unit diopters (ex. 1D or 5D), but these large increments of prism sometimes left patients feeling nauseous.

New clinical research by the NeuroVisual Medicine Institute has determined that much smaller amounts of prism are the key to resolving patients’ subtle vision misalignment. Microprism is defined as prism lenses prescribed in fractional units of prism (ex. 0.25D, 0.75D)

There is an art and science in prescribing microprism lenses, which is why Dr. Knighton takes her time during the NeuroVisual Evaluation. Once the images from both eyes are realigned, the eye muscles no longer have to strain, providing significant relief from headaches, dizziness, blurred vision and most other symptoms.

What can I expect with Prism Glasses?

While prism glasses have provided tens of thousands of patients with life-changing relief,it can take several days to acclimate to the new prism prescription. When you first begin wearing the prism glasses, your body will undergo a process of change we call Progressive Relaxation. Your BVD symptoms will start to subside as your eyes muscles allow the lenses to realign the images. After wearing the lenses for about 4 weeks, your symptoms might return, which tells us you are ready for your next exam, the Progress Assessment.

The vision misalignment measured during your initial NeuroVisual exam may measure differently during your Progress Assessment. We tell patients that “the first prism prescription is never the final prism prescription” because as your body and eyes relax, the prescription will adjust and shift. NeuroVisual lenses purchased at our office will be remade once at no additional charge, since we are expecting this change.

What is the cost of testing and glasses?

The NeuroVisual Evaluation for new patients is about 2 hours long, and includes a prescription for glasses, a written report and extensive consultation with Dr. Knighton. Progress Assessments and annual NeuroVisual Evaluations are about 1 hour long, with prescription and consultation. The evaluations range from $395 to $450.

We are not in-network providers with any medical insurance, except standard Medicare (not Medicare Advantage), so we cannot bill your medical insurance for these evaluations. Vision Plans like VSP or Eyemed only cover well-visit eye exams, so they do not cover the extensive testing for BVD.

BVD is a serious and frustrating eye condition, but there are solutions! Be rest assured that you will receive the best in friendly, professional and innovative eye care. Our doctors and staff strive to listen and help all our patients find relief from their vision problems.

TheraLens microprism lenses are cutting-edge, custom lenses designed to give greater clarity, stability and comfort. Lens options include single vision and progressive lenses, thinner lenses, blue light protection, transitions, tints and more. Most lens packages offer a 1-year scratch warranty and at least one no-charge prescription change.

In addition to the precise prescription, the doctor will recommend the best type of lens options for your visual needs. Our optical team will help work within your budget. Microprism Lenses range from $320 to $860, not including the price of the frame. Multiple pair discounts and clip-on options are available.

Bright Eyes carries a wide variety of eyeglass frames, ranging from $125 - $395, all with a 1-year breakage warranty. You are welcome to use your own frames for lenses, if they are deemed good condition by the optical department. Be aware that we will need to send the frames to the lab for up to 3 weeks to manufacture the lenses.

Please call our office with any questions. We look forward to helping you!