Although light therapy has been used worldwide for more than 40 years, its popularity for cosmetic enhancement only recently has increased exponentially. In fact, it has become so popular so quickly that most skin care professionals aren’t educated on the variety of light-based technologies available, as well as informed about who can use them legally. Lasers, intense pulsed light (IPL) and light-emitting diode (LED) treatments are three current light-based technologies that are used commonly for skin rejuvenation.
A brief review of the physics of light
The visible light spectrum is the most familiar—the wavelengths are from 400 nanometers (nm) to 765 nm, which are seen combined as white light and diffracted as a rainbow. White light is composed of colored light. Daylight and standard light bulbs give off light in this range.
Estheticians already should be familiar with the ultraviolet (UV) portion of the spectrum: 0–400 nm. These are the invisible wavelengths that cause UV damage, such as sunburns and photoaging. UV light also is used by estheticians to kill bacteria on their instruments.