Skin photodamage is damage caused by the action of certain types of light energy on the skin. Photodamage is often referred to as sun damage, but it may also include other sources of light, including those that are man-made.
As we know, the sun emits a vital source of energy that reaches Earth in the form of electromagnetic radiation. This radiation is filtered by the upper atmospheric layers, allowing only a few wavelengths to be delivered to the surface of our planet such as the visible light spectrum, infrared light, radio frequencies and some ultraviolet (UV) rays.
Ultraviolet rays. Of these UV rays, UVC (180-280nm) is mostly blocked by the ozone layer, while UVB (280-320nm) and UVA (320-400nm) make their way through. However, cloudy and overcast days can reduce the amount of UVB that hits the surface. The benefits and side effects of exposure to UV rays are presently known by industry experts and by many savvy consumers. To assess the particular action of ultraviolet light over a geographical area on Earth, a parameter has been established called UV index that supplies a daily forecast of the expected risk of overexposure to the sun. This is provided by the U.S. Environmental Protection Agency (EPA) to guide the planning of outdoor activities while considering the risk of damage from UV light.
Interestingly, the sun is not the only source of UV rays. The widespread use of certain light bulbs emitting low levels of UVA and UVB rays is now a common occurrence in many places such as the workplace, at home, public locations, etc. As a matter of fact, indoor fluorescent lighting and some halogen lamps can contribute to a certain degree of each individual’s received dose of ultraviolet exposure.
HEV light. There is also another unknown concern to many that can be detrimental: blue light exposure. Blue light is part of the sunlight spectrum that covers the 400 to 500nm wavelength. It is also known as high energy visible (HEV) light. Due to the high energy property of this light range, it can enter the skin deeply and reach the dermis where some of the most important components are located, such as: collagen, elastin, hyaluronic acid and others. This action leads to premature aging and the signs and symptoms associated with it including the early onset of lines and wrinkles, elastosis, melasma and hyperpigmentation and possibly skin cancer. Presently, this type of light is ubiquitous and produced by the everyday use of electronic devices like computer monitors, some modern television sets and smartphones.