Syntonics (optometric phototherapy) uses colored light produced by a small lamp. The typical treatment for syntonics requires a patient to sit in a darkened room and view a circle of colored light for 20 minutes, over a span of multiple sessions (usually 20 or more). Other modalities can be used to effect the same change. The treatment with light can also be administered with the combination of a certain, broad-spectrum light bulb, and color filters in glasses that are worn.

Light is a catalyst for different actions in our cells. To use this type of energy from light, it is rapidly spread throughout the body by the blood supply. Because the inside of the eyes are very vascular (having a large amount of blood vessels), 20 minutes of treatment with the syntonics light affects 40% of the blood supply.

The color of the light used in the lamp is based on the type of vision problem and the imbalance in the system. Treatment with the syntonics light can put the system back into balance.

How is it determined if syntonics can be helpful, and if so, what color filter to use?

  1. A detailed case history is taken
  2. Pupil testing
  3. Functional visual fields (i.e. How much does the brain pay attention to the visual information in the periphery)

The specific aspect of pupil function looked at is called “pupillary release.” A pupil that responds in a certain way is indicative of an imbalance in the autonomic nervous system. The autonomic nervous system has two branches. One branch is the sympathetic nervous system, the other is the parasympathetic nervous system. The sympathetic nervous system activates the ‘fight or flight’ response; the parasympathetic nervous system activates the ‘resting and digesting’ responses. The term, ‘syntonics’ was derived from the word ‘syntony’, which means ‘bringing the body into balance.

Functional visual field deficits are different than visual field loss that occurs because of pathology. With visual field loss, the signal is not being transmitted or the processing part of the brain has been damaged. With functional visual field deficits, the visual pathway is intact, the information in the periphery is mostly ignored or the brain does not fully attend to the visual information. It can be similar to looking through drinking straws or paper towel tubes. This can make eye movements, focusing, and eye-teaming difficult. It can contribute to stress and anxiety, and coordination difficulties.

This use of syntonics, or light therapy, is not a new treatment. Light has been used for medical treatment since the time of Ancient Greece. Light is used for treatment of mood disorders, such as Seasonal Affective Disorder. Light is also used as treatment in neonatal jaundice.