Color temperature is the most common indicator of the spectral quality of a light source. Generally expressed by Tc. Color temperature is defined by absolute black body. Nowadays, LED lamps and lanterns are very common in life. There are various colors, so how much LED color temperature is good for the eyes? Are led lights harmful to eyes? Don't worry, I will explain it to you in the same city below, let's take a look.
How much LED color temperature is good for the eyes?
There are reports that white cold light LEDs and blue LEDs are harmful to the eyes and should be banned. These LEDs are mainly used for decoration, and the intensity of blue light emitted by them far exceeds that of natural lighting and traditional lighting. These high-intensity blue light will cause damage to the pigment epithelium of the retina and the sensory layer of the retina at the same time, thereby accelerating retinal aging and increasing the risk of macular degeneration. The biggest victims of LEDs are children under 10 years of age. Children of this age have neither cloudy lenses nor macular pigment, so they lack the ability to resist blue light.
The LED lamp uses a blue chip and an external yellow phosphor to be mixed to produce white light, which makes the content of blue light in the LED lamp relatively high. Blue light refers to the blue light band of 400-500 nanometers. If the brightness is too high, the eyes may cause photochemical damage to the retina after looking directly at the light source for a long time. The degree of blue light hazard depends on the accumulated blue light dose received by human eyes under the light. According to national regulations, the color temperature of LED lighting cannot be greater than 4000K. However, due to the high light efficiency and relatively low cost of high color temperature LED light sources, there are many high color temperature products on the market.
Color temperature is the most common indicator of light source spectral quality. "Warm light" has a low color temperature, while "cold light" has a relatively high color temperature. After the color temperature increases, the proportion of blue radiation increases, and the blue light increases accordingly. At the same time, brightness also affects the proportion of blue light. Generally speaking, fluorescent lamps and LED lamps with the same color temperature are basically harmless as long as the brightness of the latter is not more than 3 times that of the former. However, for individual LED lamps that are too bright, the proportion of blue light may exceed the safe value. As the LED technology matures, manufacturers no longer need to blindly increase the color temperature and power of lamps to achieve high lumens, and objectively reduces the possibility of excessive blue light.
Are led lights harmful to eyes?
When parents choose eye protection lamps for their children, they often think that the brighter the light, the better. This reminds me of the story in the 1990s when we thought that the whiter the flour, the better, but now everyone knows that the whitening of flour is due to the addition of whitening. Brighteners are harmful to people. Therefore, to judge whether a thing is good or bad, one must know its internal composition to be sure.
Here I will talk about the basic knowledge of light source. The eye protection lamp protects the eyes because the high-frequency rectifier circuit makes people not feel the flicker of the fluorescence. This is Philips technology in the 1980s, and now all large and small manufacturers can do it. The key to eye protection is the color rendering of the tube and the color temperature of the light. The eye protection lamp uses a fluorescent tube. The main luminescent materials currently used are:
1. Pure three-base toner,
2. Brine powder,
3. Mixed powder of the two.
According to the cost calculation, eye protection lamps with a retail price of less than 100 yuan in the market can basically not be called eye protection lights, because eye protection lights that are not pure tri-color are actually eye-catching lights. The effect of the eye. (The price of pure tri-basic toner is nearly 10 times that of halogen powder.) I will not analyze it here. I will only talk about the color temperature of the pure tri-basic toner tube.
The light of the tri-color tube is the phosphor yttrium oxide (red light, peak wavelength is 611nm) that can emit red, green, and blue light sensitive to the human eye, and magnesium polyaluminate (green light, peak wavelength is 541nm) ) And barium magnesium polyaluminate (light emitting blue light, peak wavelength of 450nm) in a certain proportion mixed into three primary color phosphors, so as to emit light closer to sunlight. Color temperature is the human eye’s perception of a luminous body or a white reflector. Normally, from 10 noon to 2 pm, a clear and cloudless sky, in the absence of direct sunlight, the standard daylight is about 5000--5500K. But the light at this time is the most poisonous and dazzling. (See the part where the white light is close to the blue in the picture below).
Current energy-saving lamps generally use a color temperature of 5500-6500K, and eye protection lamps generally use a color temperature of 4500--5500K. Many of our consumers feel eye pain after reading under a desk lamp. The reason is that the color temperature and color rendering of the desk lamp are not good. Suitable for reading at close range. It is easy to compare the same book under lights of different color temperatures. The higher the color temperature, the brighter the light, and the more dazzling the reflected light of the writing. The lower the color temperature, the warmer the yellow light and the softer the reflected light of the writing. , The less irritation to the eyes. Through experiments, we can see that the effect of reading books is the best when the color temperature is around 4000K, and there is basically no reflected glare. And why only a few manufacturers use 4000K color temperature lamps, there are only two reasons: one is that the higher the color temperature of the lamp, the cheaper it is, and the second is that the higher the color temperature, the brighter the light looks, just like a brightener. Like flour, it looks good!
Therefore, remind users of table lamps and eye protection lamps that the brighter the lamp line is, the better. The light for reading and learning should be soft. The standard color temperature between 3800--4200K is the most suitable.
The above is the explanation of the knowledge of how much LED color temperature is good for the eyes and whether LED lights are harmful to the eyes.
