Principals and benefits

Light therapy, also known as photo therapy or lux therapy, literally means treatment through light. We distinguish two types of light therapy : that which passes through the skin (by means of ultra-violet or infrared rays) and that which passes through the eyes. It is the latter which interests us.

Light therapy uses the therapeutic properties of light (see role of light chapter) and finds its way when it is not possible to access natural light, whether it is because of their schedule or because the person lives in a region where light is rare in winter. Artificial light provides a light spectrum close to that of sunlight but is completely devoid of ultra-violet and infrared rays due to safety reasons.

In concrete terms, light therapy consists of exposing the eyes to a source of light which has a specific spectrum and intensity over a determined length of time. This source of light is generally a light therapy lamp. This could be all sizes (from a wall panel to a simple led) and all forms (from a static lamp to glasses).

The effectiveness of a light therapy session mainly depends on three parameters:

1. Time of exposure: to completely take advantage of the benefits of light therapy, it is recommended to carry out the session upon waking up, that is to say in the morning for someone who works all day. A light therapy session in the daytime will have a boosting effect comparable to that of coffee. A session in the evening is recommended for someone who works at night.

2. Light spectrum: it has been proven for a long time that photo receptors are particularly sensitive to the blue part of the spectrum. A light therapy lamp whose spectrum has been enriched in blue will require a weaker spectrum for the same effectiveness.

3.  Light intensity : light intensity, generally expressed in lux and measured at a given distance, is a very important parameter to consider when buying a light therapy device. The more powerful the light source, the shorter the session will be for the same effectiveness.

Example of a lamp placed at 30 cm: 500 lux = 2 hours; 10’000 lux = 0.5 hours

Discover what role light plays on the body,

with Roland Pec - sleep specialist and chrono-therapist