Frequently Asked Questions About BVD From Our Patients

“Why didn’t my last doctor check for binocular vision dysfunction?” 

Unfortunately, about 90% of the time, they don’t. Most ophthalmologists are not trained in binocular vision dysfunction and are more concerned about the health of the eye itself (i.e., Retina and optic nerve). The eye’s health is important and allows us to know why there may be reduced visual acuity, but it does not tell us how the eyes work together, just how each eye sees. 

“If I have 20/20 vision, then why do I still have headaches, dizziness, and anxiety?” 

20/20 vision only tells us the sharpness and clarity of vision in each eye; it does not give us any information on the binocular status of your eyes. Binocular Vision Dysfunction (BVD) includes convergence insufficiency, convergence excess, divergence insufficiency, divergence excess, vertical heterophoria, superior oblique palsy, and vertical heterophoria. These BVD diagnoses are some of the most common.

“How is BVD tested?” 

We test for BVD through a sensorimotor exam. Von Graefe testing is not an accurate way of measuring binocular vision as it does not tell us how the eyes are aligned in free space at a distance and near or in different positions of gaze. A sensorimotor exam tests for diplopia, horizontal, and vertical phorias.

“I’ve had binocular testing done by an eye doctor, and everything was fine. Why would your testing be any different?” 

Our evaluation is different than any other doctor unless Dr. Debby Feinberg trained them. Dr. Feinberg developed NeuroVisual Medicine and the protocol for measuring and treating binocular misalignments, specifically Vertical Heterophoria. Vertical Heterophoria is when the retinal images are slightly misaligned on the vertical plane. Headaches and dizziness are the most common symptoms of this binocular vision dysfunction. Through the Feinberg Method, we can measure and treat binocular misalignments to the quarter of a prism diopter. Most doctors do not have the knowledge or “toolbox” to be able to do this. 

“I have tried prism and it did not work. How is your prism different?”

Through our training by Dr. Debby Feinberg, we can measure and prescribe prism to the quarter of a prism diopter. Less is usually always more. Although people can have large horizontal and vertical misalignments, it is false to think that they need a large amount of prism to correct them. During our prism evaluation, we can trial frame the aligning prescription and use the least amount of prism to alleviate symptoms. 

“I’ve done vision therapy for convergence insufficiency, but never got any better. Why would NeuroVisual Medicine help me?”

In most of these cases, the patient has an undiagnosed vertical phoria. It is impossible to train convergence when you have one eye seeing an image slightly higher than the other. Therapy cannot train one eye to come down or one eye to come up independent of the other eye. The anatomy of our eye muscles does not work that way. After correcting the vertical heterophoria with microprisms, the convergence often gets better, too, since both eyes can then work together on the same horizontal plane.

“Can a cover test diagnose BVD, specifically vertical heterophoria?”

A cover test will not be able to detect a small vertical phoria. The naked eye is unable to see 0.25 to 1.00 prism diopter vertical phoria. Most offices also only have the means of then measuring these phorias in diopter steps of prism (i.e., 1, 2, 3, etc.). At our office, we are able to measure to the 0.25 of a prism diopter, and we do not rely on a cover test to measure our vertical phorias. We use specialized equipment that allows us to measure these minute deviations.  

Think You Have Binocular Vision Dysfunction (BVD)?

Please take the test to see if you have Binocular Vision Dysfunction