- The light power at the point (mW/cm^2) – This factor depends on the power of the light and how far away the light is from the point.
- The amount of time the light shines on a point
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The amount of light that is reflected off the point instead of absorbed
This J/cm^2 energy is what our cells use to heal themselves. Different treatments, however, require more, or less energy to do the best job of healing any ailment.
So you might be thinking that it’s better do a therapy session for longer to be safe. However, scientists have actually found that after too much red light your body stops achieving the optimum results and you could lose the benefits you gained from a session. Luckily, there is a pretty big window for optimum results. Below is a graph demonstrating how this works. Bearing in mind that the deeper tissue treatments are Near-Infrared Light doses and skin surface ones are Red Light doses.
We can now calculate the dose by using the equation: Dose = Time(s) x (Power density x 0.001)