Understanding the blue light hazard

June 14, 2022

What is exactly the blue-ray hazard?

Blue light is a kind of high-energy short wave visible light (HEV), which refers to the blue part of visible light. It has a short wavelength and is concentrated in the 380 nm ~ 450 nm band. 

For people who often engage in outdoor activities, the main source of blue light is sunlight, while indoor man-made sources include fluorescent lamps, LED lamps, and display screens of electronic equipment. Blue light, although present in our everyday life may actually have a dark side to it; certain health concerns. An appropriate amount of blue light can also let us enjoy health and vitality, especially when it falls in the 450 nm ~ 500 nm range. But going beyond the limit may make you start to feel blue since too much blue light raises health risks for the body. So, why is blue light dangerous?

Excessive HEV light radiation can cause oxidative stress response of retinal cells, irreversible photochemical damage, and even aggravate cell damage in the macula. This is what we usually call a “blue light hazard”.

What is blue light hazard

What are the criteria for judging blue light hazards?

The standard of blue light hazard can be assessed according to the optical biosafety test standard IEC 62471. IEC 62471 is a comprehensive parallel standard that describes all potential health hazards, including the ultraviolet part of the spectrum to the visible and infrared parts. According to the retinal blue light hazard exposure limit defined in IEC62471, the size of blue light injury is mainly determined by the blue light-weighted irradiance, the blue light weighted irradiance, and the duration of exposure to blue light, and the blue light weighted irradiance is equal to the value of multiplying the spectral irradiance of the blue light band by the blue light hazard weighting function, and then integrating the wavelength:

blue light hazard weighting function

In order to prevent retinal photochemical damage caused by long-term blue light radiation, the maximum allowable irradiation time:

The maximum allowable irradiation

The greater the weighted radiance of blue light, the less the maximum irradiation time allowed.


a. How does Blue Light Affect Your Eyes

Due to the length of the blue light wave, if you want to see objects clearly under the stimulation of blue light, your eyes will be in a tense state for a long time, causing visual fatigue and inability to concentrate, which directly affects our study and work efficiency. To combat this, industry professionals have developed blue light blocking glasses to advert eye strain caused by prolonged exposure. 

b. How does Blue Light Cause Conditions and Diseases?

The excessive blue light will lead to the decline of retinal epithelial pigment cells, cell death in light-sensitive areas, macular disease, fundus disease, vision loss, and even blindness. Consider proper protection of your eyes by using blue light blocking screen protectors for devices, TVs, monitors, etc.

Aggravating macular diseases

C. How does Blue Light Affect Sleep?

Blue light stimulates the brain, inhibits melatonin secretion, and improves the production of adrenocortical hormone, to regulate heart rate, alertness, sleep, body temperature, gene expression, and disrupt human physiological rhythm. The consequence is naturally unable to sleep at night and get up in the morning. It also increases the risk of diseases, especially breast cancer and colorectal cancer.

Should we eliminate the blue light?

According to scientific research, the retina of mammalian eyes includes three types of photoreceptors: cone cells that are responsible for seeing during the day, rod cells that are responsible for seeing at night, and endogenous light-sensitive retinal ganglion cells (ipRGCs) that are not responsible for seeing. These ipRGCs are not idle and have powerful functions. They sense the blue-green light components (460-550 nm) in the light source, and are responsible for reporting the brightness of the light to the brain, regulating the circadian rhythm and pupil contraction, and affecting our sleep, mood, and learning ability. This is why blind people can also feel day and night changes, and there is also pupil reflex to light.

460-500 nm blue light is beneficial! Blue light therapy or blue light treatment has been used in the medical industry to cure skin conditions and even depression. Blue light can stimulate the spirit and reduce depression, so it is used to treat seasonal mood disorders (winter depression). Blue light can improve sleep quality. With the growth of age, the lens of the eye turns yellow, the absorbed blue light increases, the blue light entering the eye during the day decreases, and the secretion of melatonin is affected. Therefore, the elderly are prone to sleep disorders.

Blue light is an indispensable element of natural light and white light lighting. Since the birth of human beings, they have been living under natural light with blue light. How can we effectively avoid the harm of blue light without affecting our full use of it?

Yuji Lighting SunWave™ series, designed for regulating the Blue light hazard

Based on the Yuji Lighting SunWave™ technology, we’ve innovated our technology to bring you blue light LED that adequately avoids the hazard. The tailor-made spectrum increases the 480nm and reduces the 450-460nm energy which is recognized as the main wavelength of blue hazard, therefore the Yuji Lighting SunWave™ series is not only helping with concentrating,  but improving the healthy lighting simultaneously. 

Yuji Lighting SunWave™ Spectrum
Yuji lighting SunWave™ spectrum

As shown in the spectral power distribution above, the SunWave™ series are designed at the spectral level to limit the disruption to restful sleep by utilizing a proprietary blend of long-wavelength phosphors. The result is a spectral distribution that produces natural light, but simultaneously limits the impact on melatonin suppression. With a 2700K color temperature and 98 CRI rating, objects appear natural and vivid. Check out our  SunWave™ series for more information!

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