With the myriad intense pulsed light and laser devices on the market, it's easy to lose sight of the differences between the two.

The healing properties of light have been recognised for thousands of years. The Greeks and Romans both understood that sunlight could play some remedial role - although there was little understanding of why.

As early as 1903 scientists realised that light could be used for therapeutic treatment. The same year Danish physician Niels Finsen Ryberg was awarded the Nobel Prize for his work on light therapy and he developed a machine that could emit similar wavelengths to the sun.

In 1917, Albert Einstein theorised on the stimulated emission of radiation, or what we commonly refer to as ‘lasers'. Today lasers are used in a multitude of products and systems from CD players to barcode scanners. Laser is an acronym for Light Amplification for the Stimulated Emission of Radiation and is used in the beauty industry for an array of treatments ranging from the correction of skin irregularities, pigmentation and wrinkles to hair reduction.

Nikola Tesla first conceived the idea of intense pulsed light (IPL) in the early 1900s and presented his idea to the American army for defence. He believed that light energy could be launched to intercept a flying object, instantly vapourising it. However, it was not until a group of Russian-Jewish physicists, after migrating to Israel, implemented the idea of using intense pulsed light in medicine, paving the way for IPL.

Pulsed-light machines and lasers basically work in the same way. Put simply, a wavelength is selected that is readily absorbed by the target tissue. Both aim to heat the target to a temperature high enough to destroy it without damaging the adjacent normal tissue.

The difference between the two is that a laser emits a single frequency of light that is coherent. All the light waves are going in the same direction, allowing the target tissue to absorb the maximum amount of heat. The target tissue is all-important when treating skin problems with a laser. The target tissue for pigmentation is melanin, for spider veins it is blood and for wrinkles water. Each of these target tissues absorbs a different wavelength of light, meaning a different laser is needed for each specific problem.

Unlike lasers, IPL devices produce a broad spectrum of light in a range of wavelengths. The emitted light is further adjustable through the use of filters, allowing any skin colour to be treated. This versatility allows the characteristics of the light energy to be adjusted according to each patient's skin type, specific condition and location of the condition on the body. Another difference is in the area that can be treated in one session and the treatment speed. Generally IPL treatment heads are up to eight times larger than the small spot produced by lasers and therefore treatments are much quicker.

In terms of safety, the two types are similar, but with lasers both the practitioner and the patient need to use eye protection, and treatment needs to occur in an area where people can't wander in and be exposed to the light. Although light from IPL systems may be unpleasant, it's not harmful or dangerous to the eyes.

While lasers and IPL treat many of the same conditions, IPL is a single technology for a multitude of applications, from unsightly veins and birthmarks to ageing and sun-damaged skin, unwanted hair and rosacea.

Bella Beauty Magazine #9