Used As Intended, LED Lights Are Perfectly Safe
Early in the development of Light Emitting Diodes (LED), the rumor started that LEDs are bad for human eyes. Unfortunately, this misinformation continues to spread. Some people say that because some people claim to see a halo around a blue LED, this proves the theory. The reality is that there is no definitive proof that LEDs used properly routinely cause eye damage.
It is true that LED light intensity is not standardized. It is true that some irresponsible writers have wrongly compared LED lights to looking directly at the sun. It is true that the industry monitors itself. It is true that staring directly at an LED is not a great idea. But, most importantly, it is true that there is no scientific proof that LED lights cause eye damage.
There are two factors that contribute to the effect LEDs have on human eyes: wavelength and intensity. Wavelength is the motion of the light through the environment that causes humans to see different colors. Intensity is the brightness of the light. The sun is more intense than is a candle flame.
LED intensity standardization would help consumers to be able to select LEDs that would produce exactly the brightness of light that they require for each use. Currently, consumers ready to buy an LED in, say, the blue range, could choose one that is too bright for their specific use, or could pick one that does not provide enough light. Without standardization there is no way for a consumer to differentiate between an LED that is super-intense and one that is barely lit.
The problem with this variable intensity is that consumers can end up with an LED that is too bright for their planned use. Using any type of light source that is too bright, or too dim, for the intended use can cause eyestrain and possible damage. But, is the LED responsible for the person’s misuse of it? Hardly.
As for wavelength being a contributor for alleged eye damage, it is true that ultraviolet and infrared LEDs can be dangerous, but there are standards in place for these types of LEDs. Also they are usually not available for casual consumer use. One bit of misinformation circulated about LED ultraviolet lights is that they give off radiation! The truth is that they produce only “near UV” light and at a level well below the threshold that might cause any harm. Additionally, LEDs produce less radiation than any other type of available light bulb.
An interesting study supported by the French Agency for Food, Environmental and Occupational Health & Safety (ANSES), “Light-emitting diodes for domestic lighting: Any risks for the eye?” in 2010, showed that the vast majority of products using LEDs are “safe under all conditions of normal use,” and so are classified as “Class 1 LED product.” The French group’s only cautionary recommendation was to suggest avoiding the use of LEDs in the moderate risk group (2) in places where children are frequently. This includes extremely bright (intense) LEDs, specifically those with a high blue component.
But what about that blue halo that some claim to see? First there are number of eye issues that might cause people to see halos around bright lights of any type. These possibilities include dry eye, eyestrain, corneal diseases, cataracts and refractive errors. But only an ophthalmologist can diagnose these for sure.
Actually people see halos around many types of lights, not just LEDs. Usually these are caused by the light fooling the human eye into seeing the difference of the light and dark spaces incorrectly. The human brain then, in efforts to try to make what the eyes are telling it into a form it can understand, creates the halo.
By: Brian Newman
