Syntonic Photo therapy was developed by Dr John Downing during twenty years of research and clinical observation. From 1969 he was Director of Vision Research at San Francisco’s Perceptual Therapy Institute.

When the optic nerve is stimulated by light a ‘photocurrent’ is transmitted not only to the visual cortex but also to other brain centres, including the hypothalamus. The hypothalamus governs the autonomic nervous system, the pineal gland and the  limbic system.

Syntonic phototherapy uses coloured lights of  various wavelengths to stimulate the hypothalamus and therefore other areas of the brain. Syntonic phototherapy balances the sympathetic and parasympathetic nervous systems.