Vision – the missing link

About 10 years ago, I treated a patient with a vision dysfunction, who was simultaneously being treated for temporomandibular joint (TMJ) disorder. The patient did some research and sought my help after finding out that TMJ and vision dysfunctions often coexist [1]. While TMJ symptoms are typically generalized to jaw pain, TMJ may increase pressure behind the eyes, resulting in headaches, light sensitivity, and even binocular dysfunctions. My work centers around the treatment of these vision dysfunctions, and this patient connected me to TMJ and sleep apnea dentist Dr. Ira Shapira. We have worked jointly with patients ever since.

Patients are commonly referred to me for an evaluation because of the obvious clarity issues. The less obvious reason patients benefit from a behavioral vision evaluation is because information is unknowingly being reduced or distorted when it is sent from the retina to the brain. The retina is formed from brain tissue, and from this formation there are 10 visual pathways that communicate information to the rest of the brain. This information is not dependent upon the acuity or clarity of an individual’s sight, but is rather information that allows one to calculate for and understand where they are in space.

These 10 visual pathways are nested inside our two vision systems. Colwyn Trevarthen [2], a neuroscientist at Harvard, was the first to delineate between these two vision systems. He firstly identified the focal vision system, which is concerned with details, and secondly the ambient vision system, which is concerned with interpreting our surrounding space. The focal vision system is a limited area in the retina whose job is to identify details and send information to the occipital and cognitive areas of the brain. The ambient vision system sends information to the superior colliculus in the midbrain to orient the head and eyes, and then on to the cerebellum to direct posture, balance, and movement [2]. While the practice of behavioral optometry deals with both vision systems, my practice is primarily concerned with how one uses their vision to take in information, comprehend this input, and correspondingly respond to said input.

Generally, there are two ways to see the world spatially: A) One sees objects and the space around them simultaneously, or B) One sees the world in a fragmented fashion – there is confusion as to where things are in space and a miscalculation as to when an event will occur. When one sees the world in this fragmented fashion, the world is reduced in three-dimensionality, and functional visual fields are diminished. Those that fall into the latter categorization have weak spatial comprehension. Our spatial comprehension is dependent on the simultaneity of recognizing both the object we are centering on and the space surrounding said object, and thus, comprehensive vision requires a fully three-dimensional and all-encompassing view of space.

Therefore, vision is externally projected into space to instruct us where and when to do something; a primary purpose of vision is prediction. Consider operating a vehicle – our vision signals to us when and where to alter speed, change lanes, and when it is safe to make a left-hand turn. However, projection is not solely an external practice. Vision internal projection is the infrastructure to both the abstract world (as in our ability to center on a tree but see the forest simultaneously) and our ability to plan and organize. The 10 visual pathways from the retina govern our ability to move comfortably through the world, as they are responsible for managing cognition and communicating with areas of the brain dealing with cognition, posture, balance, movement, speech and language, and emotions and feelings [3]. Thus, when there is an inability to subconsciously coordinate information from each eye, a visual dysfunction is born [4].

The most common dysfunction I have seen in my 50 years of practice is collapsed functional visual fields; I have coined this visual dysfunction “tunneling.” Tunneling is a maladaptation of the visual processes caused by intellectual, psychological, or physical stressors, which results in an abnormal subconscious sensory-motor organization [5]. Tunneling is a prevalent adaptation in those suffering from refractive, binocular, and monocular disorders.

While TMJ sufferers are not straightforwardly wrestling with refractive, binocular, or monocular disorders, the increase in pressure behind the eyes that is a possible symptom of TMJ breeds a sort of vision dysfunction. TMJ sufferers frequently complain of light sensitivity; this sensitivity to light parallels overstimulation. If light is analogous to information, one who is sensitive to light is incapable of working in a brightly lit area because, in this situation, they are being asked to process too much information at once. This sensation of overwhelmingness resulting from too much light causes one to tunnel, creating a vision dysfunction, which plagues patients with its myriad of painful symptoms.

These vision dysfunctions are treated with performance lenses and visual training. Performance lenses help one organize spatial information more appropriately and induce more adequate responses to situations (as opposed to lenses prescribed with only acuity in mind, which distort the information the retina receives). These performance lenses aid in an improved integration of the focal (central) and ambient (peripheral) vision systems [6,7]. Although performance lenses assist in increasing comprehensive vision, often, additional treatment is necessary. To restore proper vision function, a visual training regimen is prescribed; this regimen consists of an array of neurosensory and neuromuscular activities, wherein the patient wears different combinations of lenses and prisms in order to recalibrate the visual pathways. While merely performing these activities is beneficial, I have observed that the most meaningful changes in my patients follow their description of changes happening in their external and internal world as they work through the visual training activities. I prompt these observations by asking questions such as, “What do you see?” “What do you feel?” “What is happening to your posture, balance, and movement as you do the activity?” The inherent nature of these questions value observation of the visible and internal world over logic, reasoning, and rationalizing. When a patient verbally chronicles the changes occurring with their external sight and/or internal emotions, their vision system can more quickly be restructured and recalibrated.

This comprehensive process approach, wherein the trainer plants questions for the patient to consider, along with an emphasis on balance and movement while performing activities, slowly liberates the patient from the distress caused by a visual dysfunction. When TMJ onsets vision problems, or if pre-existing vision problems are coupled with TMJ, this combination severely compromises patients. Behavioral optometry is a practice of perceiving, processing, and performing, and this comprehensive process approach imposes perceiving and processing onto patients, such that they can better and more confidently perform in all areas of life.

Disclosure statement

No potential conflict of interest was reported by the authors.