(1) Illuminance: Sunlight illumination refers to the energy of visible light received per unit area. In the national architectural lighting design standards, there are detailed illumination standards for different architectural occasions, such as library reading rooms, school classrooms, blackboards, hospitals and so on. In the living room for writing and reading, the illumination standard of 0.75 horizontal plane is 300lux mixed illumination.
(2) Scattered sunlight with color temperature of 10 am is the most comfortable light for human eyes. The average color temperature of scattered sunlight at 10 in the morning of a year is 4000 ~ 4200 K. Too low color temperature will cause people to be tired and sleepy under the light. Moreover, too high color temperature will make people highly nervous and tired in the light.
(3) Color rendering: The color rendering index of sunlight is 100 in theory, and the measured value is 98.5. The higher the color rendering index, the more true the color of the object can be restored.
(4) Luminous form: Grandpa Sun always glows and never rests, so there is no flicker, that is, no stroboscopic. There is a very simple way to test whether there is flicker: aim at the main light with a mobile phone with camera function, and you will find that the ordinary light will have obvious flicker.
(5) Spectrum (blue light that everyone cares about): Sunlight contains all kinds of visible light (including blue light), so you don't have to be too nervous about blue light. According to the intensity of blue light, the international photobiological safety standard of blue light is formulated, and various values that may cause blue light harm are set. For example, light source products without blue light hazards are called "zero category products" (RG0); Products that are less harmful to blue light and whose eyes can't look directly at the light source for a long time are called "Class I products" (rg1); The light source that is harmful to blue light is called "Class II product" (RG2).
(6) Glare: Glare is not a light source, but a concept for lamps. A good desk lamp should be treated with anti-glare, or use a light guide plate or a diffuser plate.
According to the above standards, you can choose a satisfactory eye protection desk lamp! Anything that only emphasizes one point, such as no blue lamp and no strobe lamp, is not a perfect eye protection lamp. After excluding most of the so-called "eye protection" lights in the market (including some well-known brands), I sincerely recommend a brand of eye protection lights: one-person e-lights.
All aspects of data pro-test, perfectly match the above sunshine index, it can be said that the natural light can be restored to the greatest extent:
(1) illumination, reaching the A-level standard of the national CQCP visual work desk lamp, and the illumination reaches 350~500lux, which fully meets the lighting needs of children's healthy writing. At present, it is estimated that there are no more than 9 table lamp brands certified by CQCP in China.
(2) The color temperature is 4000K.
(3) The color rendering index exceeds 97, and CREE (American listed company) LED chip is adopted.
(4) No stroboscopic, using 12V low-voltage DC, with soft light.
(5) Adopt direct light, and use imported light guiding film diffusion technology to suppress blue light to the greatest extent. According to EU EN6247 1 Photobiological Safety Certification, the hazards of blue light and electromagnetic radiation are RG0 harmless standards, and the blue light index is lower than that in sunlight.
(6) Use a diffuser without glare.