Most of our lives are immersed in the world of light: during the day, we are bathed in the natural light - sunlight, as if the body is "photosynthesizing"; At night, we light a lamp to let the days of solitude shine brightly. The table lamp is like the guardian of the night, illuminating the night with a soft light, bringing warmth and companionship to the lonely night.
However, the guardians who accompany us through countless dark nights can also be the "perpetrators" of our eye health. Whether the desk lamp that is close at hand will escort our work and study or make our deteriorating vision health "worse" depends on our choice of table lamp, especially for the table lamp of the flowers of the motherland - the desk lamp for reading and writing.
First of all, let's understand what is a "reading and writing desk lamp". To put it simply, it is actually a desk lamp for children to do homework at night. On December 30, 2022, the revised recommended national standard GB/T 9473-2022 "Performance Requirements for Desk Lamps for Reading and Writing Operations" (hereinafter referred to as the "Requirements") was officially released and will be implemented on January 1, 2024. Previously, the 2017 standard was implemented, and now the main changes in the 2022 standard are:
(1) The illuminance level is now changed to the luminosity level, which is actually a modified noun and does not need to be specially recorded.
(2) The requirements for illuminance and illumination uniformity have become higher.
The figure above is the required data on illuminance and illuminance uniformity in the standard.
GB/T 9473-2022 further regulates the market standard of the reading and writing desk lamp industry, and makes detailed provisions on its photoelectric performance, including lighting comfort, impact on human health, and the most basic photoelectric properties. Secondly, let's take a detailed look at the specific light quality requirements of the desk lamp for reading and writing homework, so that we can choose a more suitable desk lamp for children to study.
1. Light-shading and anti-glare
When using a desk lamp, if the brightness of the individual parts that are visually visible to the table lamp is too high, it will produce glare, causing visual discomfort. The desk lamp for reading and writing should be light-shading and free of excessive glare.
When you enter and exit the tunnel, you can't see clearly, why can't you see clearly? It's because of the presence of glare. There is no glare in most road conditions, and it is generally in tunnels, garages and other scenes with alternating light and dark.
Now the solution of eye protection table lamp manufacturers is to add an anti-glare film to the lampshade part to achieve a glare-free effect.
2. Illumination and illumination uniformity
If the illumination of the desk lamp is too dim, it will not meet the lighting requirements, if it is too bright, it will stab the eyes, and the illuminance is positively correlated with the value of "minimum horizontal illumination" in the table, the larger the value, the greater the illumination, the higher the brightness. According to the national AA lighting requirements in the above table, the minimum horizontal illuminance (unit: lx) of the central area should be greater than or equal to 500lx, the minimum horizontal illuminance of the total area (within a radius of 50cm) should be greater than or equal to 250lx, and the maximum horizontal illumination should not exceed 2500lx. Illumination uniformity literally means that the light is not uniform enough, and the uniformity is negatively correlated with the values in the table, and the smaller the value, the more uniform it is, and it is not easy to fatigue in this lighting environment. The illumination uniformity standard of the value AA level is: the central area is less than or equal to 3; The total area is less than or equal to 7.
Keep in mind that the closer the illuminance uniformity is to 1, the more uniform the illuminance and the more comfortable it will be for the eyes.
3. Color rendering index
The color rendering index is the reduction degree of the light of the eye protection desk lamp to the color of the object, and if the color rendering index is too low, you will not be able to see the color, which will lead to visual fatigue for a long time. Generally, the color rendering index Ra should not be less than 80. For products with LED light sources, the special color rendering index R9 should be greater than 0. The measured value should not be lower than the claimed value.
Let me note that both Ra and R9 are as close to 100 as possible, and 100 is the highest value.
Ra is the general color rendering index, and R9 is the color rendering index of positive red.
Fourth, color temperature
Color temperature is the temperature of light, and the color temperature index is different for different application scenarios. Generally speaking, light with a high color temperature is more likely to keep people excited, and light with a low color temperature at night is less likely to interfere with sleep. Standard recommendation: The color temperature of the lamp used at night should not exceed 4000K.
5. Flashing
All light sources that operate under alternating current produce flickering. Working under flickering light, human eyes are easily fatigued and even cause physical discomfort. The standard uses indicators such as fluctuation depth and transient light artifacts to regulate the flickering of desk lamps.
Let me give you a direct answer: the optical output waveform frequency >3125Hz can be defined as no video flash in terms of strobe, which is qualified.
6. Retinal blue light hazards
Let me tell you first, not all blue light is harmful, harmful blue light refers to blue light in the wavelength band between 385-445nm. Blue light in this band penetrates the lens to the retina, potentially causing irreversible damage to vision.
Now the blue light excited LED eye protection lamp is generally coated with an anti-blue light filter inside, and then the color temperature is reduced to send it for inspection, although the blue light level can reach RG0, but some table lamps have not fundamentally solved the blue light problem.
The blue light peak of the LED table lamp excited by violet light will be relatively low.
OLED eye protection lights are superior, and there is basically no blue light problem. But now manufacturers rarely produce, because the cost is relatively high.
Now the reliable products on the market are blue LED with Purui lamp beads, purple LED with sunlike lamp beads.
7. About the choice of eye protection table lamp.
I believe that after reading the above content, you should know how to choose an eye-protecting table lamp.
If you want to save more time, you can take a look at the BenQ MindDuo eye protection desk lamp, Manshuyu k1 series table lamp, and lipro eye protection table lamp, these three product product data are very good, it can be said that it is much higher than the national AA standard products. You can move to the e-commerce platform to take a look.
lipro Eye Care Table Lamp National AA Grade ¥1874 Buy
epilogue
In the end, it is said that children's height, eyesight and teeth are the three mountains that press on parents in the new era. By reading this article, I believe that parents will gain something, and they can also be more handy when choosing their children's reading and writing homework lamps, so naturally one of the three mountains on the body can be solved.