With only our own human perceptions to gauge reality, some of us don’t realize that our version of reality is just a combination of measurements defined by the resolution of our senses. We are confined to our own perceptions and the version of reality we see or perceive, through the functions of our various organs, may actually be imperfect and is probably a very dim version of true reality. We cannot actually see through another life form’s eyes, at least not yet, but through science we can make a close approximation. We can do this by studying how other animal’s eyes are built and how they function, like looking at the number of cones and rods or the shapes of their eyes or pupils and then comparing them with our own. Also, the invention of different types of cameras and handheld flashlights facilitate humans with the ability to observe with different types of light filtration, for example the UV spectrum, which animals like bees see with. Naturally this would be impossible for a human, but science and technology have revealed many wonders and many perspectives to us.
A common question regarding ultraviolet LEDs is: Do they pose any safety risks? As described above, there are different levels of UV light. One of the most commonly used and familiar sources for producing UV output is the “black light bulb”. This product has been used for decades to produce a glowing or fluorescence affect on specific types of posters as well as for other applications such as the authentication of paintings and currency. The light being produced by Understanding Ultraviolet LED Applications and Precautions
these bulbs is typically in the “upper” UVA spectrum which is nearest in wavelength to the visible range with relatively low energy. This portion of the UVA spectrum is the safest of the three various spectra of UV light, although high exposure has been linked to skin cancer in humans as well as other potential issues such as accelerating skin aging. LEDs (as opposed to standard incandescent or fluorescent type bulbs) are also highly directional with very narrow viewing angles. Looking directly into a UV LED can be harmful to the eyes. It is best to limit exposure to UVA producing product.
The UVC and much of the UVB spectrums of light are primarily used for germicidal and sterilization purposes. Light produced at these wavelengths are not only harmful to micro-organisms, but are dangerous to humans and other forms of life that may come in contact with it. These LED lamps should always be shielded and never be viewable to the naked eye even though it may appear that little or no light is emanating from the device . Exposure to these wavelengths may cause skin cancer and temporary or permanent vision loss or impairment.
All UV devices should have warning labels similar to the label shown below (provided by Marktech Optoelectronics). In addition, prior to purchasing a UVC or UVB LED, many manufacturers requires that each customer sign a document stating they understand and agree to the precautions regarding the use and handling of these products.