Red light and near-infrared light (NIR) are both forms of light within the electromagnetic spectrum, but they differ in wavelength and how they are absorbed by the body.
1. Wavelength
Red light has a wavelength between 600 and 700 nanometers (nm), and it is visible to the human eye. It has a warmer, more visible appearance.
Near-infrared light has a longer wavelength of 700 nm to approximately 1,200 nm. This lies just outside the visible spectrum, making it invisible to the human eye, but it still has a great deal of energy and can penetrate deeper layers of the body.
2. Penetration into the body
Red light penetrates the skin to a depth of approximately 5 millimeters. It is primarily used to stimulate the superficial layers of the skin, such as improving skin texture, collagen production, and reducing inflammation.
Near-infrared light can penetrate more deeply, up to 2-3 centimeters into the body. It is often used for muscle recovery, joint pain, and improving blood circulation in deeper tissues.
3. Applications
Red light is often used for skincare and promoting healthy skin, for example by stimulating collagen production and reducing inflammation.
Near-infrared light is often used for deeper tissue recovery such as muscle and joint pain, promoting blood circulation, and speeding up recovery after physical exertion or injuries.
4. Effects on the body
Both types of light have therapeutic effects, such as promoting cell recovery and reducing inflammation. Near-infrared light, however, has a greater effect on deeper tissues and is often used for pain relief, while red light is more focused on skin improvement and superficial regeneration.
In general, they are often used together in combination therapies to benefit from both superficial skin improvement and deep tissue therapy.