Heavy schoolwork, and the overuse of electronics, has led to more and more "small glasses".
As parents try to control their children's access to electronics, they are becoming more selective about the lamps they use to study, and eye lamps are beginning to catch on.
In lamps and lanterns market, to protect an eye lamp, businessman hit in succession "do not have frequency flash" "prevent myopia" "protect an eye" wait for promotion sign, its design diversity price is uneven also, often let the parent that wants choose and buy feel dazzling, do not know how to begin.
How should the lamp that gives the child learns to use choose after all?
Does the eye lamp protect the eye after all?
Illumination is graded A and AA
What does it mean that parents care about brightness, color temperature, and blue light when choosing eye protectors?
Outdoor lighting can be more than 100,000 lux when the sun is shining, and hundreds of lux when it's indoors.
Lux is a unit of light intensity.
The average illumination on the desk in the classroom should be no less than 300 lux, according to the current hygiene standards of lighting and lighting in primary and secondary schools.
Illuminance, simply speaking, is enough light.
The higher the illumination, the better the visual perception and the higher the efficiency.
And illuminance even degree, reflected the light and shade condition of lamplight distribution.
The pupils of a person's pupils will contract because of the difference in light. If the light is not uniform, the pupils will be constricted continuously and the eyes will get tired easily.
The smaller the illumination uniformity value is, the smaller the light and dark changes emitted by the lamp, the more comfortable the human eye is.
Illuminance is in "gb-t9473" (the performance standard of reading and writing desk lamp) that implement on April 1 this year, cent A class and AA class two grade.
Up to 300 lux is A level, that's the lowest line, AA is going to be higher, 500 lux, and AA is going to be better than A level.
There are four levels of blue light damage
Inside the retina, light-sensitive cells have blue light.
Too strong blue light, or too strong ultraviolet light, not good to the human eye.
Blue light is a component of white light, which cannot be completely eliminated. Only too strong blue light and long-term blue light exposure will affect the safety of the eyes, while the main source of blue light in eyes is TV, computer and other screens.
According to a large number of fundamental researches conducted by the international lighting institute, the blue light hazard of lighting products to human eyes is divided into four levels: no danger (RG0), low danger (RG1), medium danger (RG2) and high danger (RG3).
The blue light that parents care about is obtained by using a spectrograph and analyzing the data.
If the blue light is less than 100, it means that it belongs to the danger level zero, that is, no danger. Generally, the lamp is required to be RG0, that is, it cannot exceed 100.
RG0 is nothing.
Up to now, RG0 and RG1 are qualified products in the standard.
The higher the brightness, the better
From the perspective of color temperature, different colors of lights have no significant effect on the progress of children's myopia.
The main risk factors for myopia are high intensity, close work, and it would be better to spend less time reading and more time outdoors.
The color temperature value of the lamp is also the color of the lamp, as long as when using, let a person feel comfortable ok, do not have too big effect to protect the eye.
In our opinion, the brightness is not dazzling, or bright or not bright, in fact, this is our subjective feeling. The gb-t9473 standard gives a limit value, suggesting that the brightness should not be higher than 2000 candela per square meter.
A specially calibrated imaging intensity meter is needed to detect the brightness. It can take continuous photos in a standard design scenario, and the brightness data of each picture will be analyzed by the computer, so that we can know the brightness of the lamp when we use it.
Brightness is not the value is higher the better, or the lower the better, when the actual choice or should be subject to subjective feelings, see whether the light is dazzling.
And 300 millimeter and the illuminance of range of 300-500 millimeter, evenness, it is a set of necessary index, use to detect the illume performance of desk lamp.
For example, how to determine whether there is strobe, we need to use an oscilloscope and a photometric probe to measure the strobe. If a flat line is shown, it means that there is no strobe. For ordinary LED products, the strobe is not obvious, unless its power supply is not good.
How to avoid glare
Glare is an important index to evaluate lamp performance. As the light source itself, the higher the brightness, the more obvious the glare.
The closer the light source is to the line of sight, the more obvious the glare.
How to avoid glare?
The child sits in the normal reading and writing position and looks at the light.
Next, the lamp with shading accessory can be considered, such as setting lens, grille and other anti-glare measures, increase the lamp cutoff Angle, reduce glare;
Do not use naked light bulb directly, avoid direct light.
Additional, also should notice when choosing desktop material to pledge, do not choose as far as possible have burnish desktop, can reflect the brightness of lamps and lanterns, ceiling and wall, produce reflection dazzle.
How do consumers select lamps
Color temperature is not particularly important performance indicators, so consumers can choose yellow or white light according to their own habits.
The color index is used to measure the color performance of an important indicator, which is whether the color under the lamp is closer to the color under natural light.
The closer this value is to 100, the better. The higher value indicates the better reduction of the object's color, indicating that the color seen under this light is less different from the color under natural light.
Tell from professional Angle, do not have actually protect an eye lamp, also do not have which lamps and lanterns to have the special effect that protect an eye.
So-called "protect eye lamp", real name is read and write work desk lamp, belong to the illume product of a kind of general use in civilian lamps and lanterns.
Choose the lamp to see the package first, 3C pattern cannot be little, if still have write reference standard, blue light harm class, and the product is concerned about color index, illuminance, even degree and so on numerical value, that product is more worthy of trust.
In addition, if the national AA level is marked, the product is more secure.
Look in many parents, lamplight too dark can affect the eyesight of the child, when desk lamp of choose and buy then, often can one-sided pursuit lamplight brightness, feel lamplight brighter affirmation to the child's eyesight is better.
Actually such idea is incorrect, because too bright light is also one of visual fatigue sources, long-term use will affect the normal development of children's vision.
In the desk lamp of choose and buy besides cannot choose the desk lamp that illuminates too bright outside, also had better not choose pure white lamplight, pure white desk lamp has the problem that the light is too bright likewise, stimulate the eye of the child, affect eyesight.
The illuminant of desk lamp had better show light yellow light, blue white light has certain damage to the human eye, had better not buy when desk lamp of choose and buy.
When buying lamp, still can try direct at illuminant.
If you find that its output brightness makes the eye more comfortable when looking directly at it, consider buying.
When choosing lamp, need not care wattage too actually, when looking directly at illuminant however, see whether to feel dazzling, if dazzling be about to choose cautiously.
In addition, there are some options for blue ray overflow problems.
If it's a naked light bulb, there's a high risk of blue light, and if it's done with some optical manipulation, the blue light hazard is basically something that can be controlled, so it's recommended that you still buy those lamps that have some invisible light beads on them, or that are not exposed to the outside.
Still some consumer oversight a bit, whether chimney is covered to live lamp body, this is very important element actually, if chimney cannot cover lamp body, so the eye can be affected by strong light direct shoot, the eyesight that affects user.
The height of desk lamp is also cannot oversight element.
Normally, when the eye is apart from the book 30 centimeters, can see the handwriting already, also won't excessive fatigue, calculate with this, the height of desk lamp is written 40, 50 centimeters is more appropriate, such make sure already enough reading illume, the environment around also has certain brightness.
The desk lamp is too low, the light irradiates the scope is small, the surroundings is completely dark.
Lose the reference that can be able to look far, can make eye each adjusting system is in the nervous compressed state that sees only close place, the eye can feel fatigue quickly, accumulate quickly, cause "illuminative sex myopia".
Desk lamp is exorbitant, although have eligible chimney to also be used, the light can illuminate our eye directly likewise, produce dazzle light, and close distance strong light still can cause on retinal bright stop phenomenon, the eye muscle of long time is contracted, more bad to the eyesight of children.