Blue LED technology was only developed in 1998. In 2014, Japanese scientists such as Isamu Akasaki were awarded the Nobel Prize in Physics for developing blue light emitting diodes (LEDs). LED lights are a new type of light source after incandescent lamps, fluorescent lamps, and energy-saving lamps, with high luminous efficiency.

From a spectral perspective, the light emitted by LEDs is very different from that emitted by traditional incandescent and fluorescent lamps. The so-called "spectrum" refers to the fact that the light emitted by an object corresponds to a "rainbow" - the light emitted by traditional incandescent and fluorescent lamps, like sunlight, has seven colors of "red, orange, yellow, green, blue, purple". But typical LED lights only have three colors of light: red, green, and blue. Among them, the shortest wavelength "blue light" is the most fundamental and important.

The photon energy of blue light is relatively higher than that of red and green light, so manufacturers often use blue light to "excite" other colors of light in order to improve the brightness of LED lights. This can easily lead to a problem of "excessive blue light" - sometimes LEDs that appear to emit white light actually contain strong blue light components in their spectrum.

Long term exposure to blue light can cause photochemical damage to our retina. This photochemical reaction produces a large amount of cytotoxic free radicals, which disrupt the normal growth and function of retinal cells. Long term exposure to blue light can damage the epithelial cells of the retina and even cause macular degeneration.

Generally speaking, products from legitimate manufacturers that have undergone national quality inspection and are listed on the market do not have the hidden danger of excessive blue light. But in daily life, there are many light sources that can emit blue light - bathroom heaters, flat panel displays, LED neon lights, fluorescent lights, LCD displays iPad、 Large screen phones and other devices all have background light sources, which contain shortwave blue light. But we should still avoid looking directly at the light source with our eyes and pay attention to the usage time. We should close our eyes and rest for a while every 20-30 minutes.

How to determine excessive blue light in LED lights sold in the market is a complex issue that is difficult for ordinary consumers to judge. I can only suggest that when purchasing LED lights, choose lighting fixtures with low blue light intensity - the most direct method is to use a spectrometer to measure the spectrum of light emitted by the LED lights.