Light action light
LED lighting is already used in schools, but not yet allowed in kindergartens and hospitals. The fact that LEDs shine well is well known, the non-visual effect of LED light is discussed.
Under the review of the mechanisms of the non-visual action of light: photodamage and effects on the circadian system.
Photodamage:
Electromagnetic wave energy can damage biological tissue. Either a large amount of light, or its concentration on a small area, or illumination with high-energy quanta are dangerous.
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A lot of artificial light is rare - for reference, offices illuminate at 300 lux and normal ambient light in the middle zone on a sunny day in the shade of 10,000 lux.
To concentrate a lot of light on a small area of the retina is simple - look at a bright object. Bright means a light that emits a lot of light from a small area, such as a filament lamp or a LED. The optical system of the eye will project a bright object onto a proportionally brightly lit part of the retina and - hello discomfort and photodamage. Reversible at low dose and irreversible at high.
The projection of the image of a bright object on a proportionally intensely lit part of the retina.
Dangerous blue component of white light - close on the scale and properties to ultraviolet. The quantum energy is greater, the probability of launching photochemical reactions is higher (ultraviolet itself is not dangerous for the retina, since it is filtered out by the lens).
How dangerous spectral components are spelled out in GOST R IEC 62471-2013 “Lamps and lamp systems. Photobiological safety.
Spectral weighted blue hazard function for retina B (λ) and thermal hazard R (λ)
You can not talk about "R", because for thermal damage you need well a lot of light, the photochemical danger curve "B" is more interesting. Opponents of LED lighting claim that the blue component in the light of LEDs is greater, which means photo danger, other things being equal, is higher. This myth dispel below.
Photodamage of the retina by LED light is a real danger, provided there are high-power discrete LEDs in sight. Subjectively perceived sign of photodamage - discomfort when looking at bright LEDs. Uncomfortable - do not look! And cover the LEDs with a diffuser.
Diffuser reduces the brightness of LEDs by several orders of magnitude. For example, office lamps 60 × 60 cm (area 3,600 cm 2 ) with a typical maximum luminous flux of 3,600 lm fit the standard for brightness of 5000 cd / m2 according to GOST 54350-2011 for ceiling lamps. Convenient ratio - 1 LM per 1 cm 2 .
By analogy, we conclude that a lamp is safe if one square centimeter of a diffuser emits no more than one lumen of luminous flux. If less - the lamp is lightweight and comfortable, if more - bright and uncomfortable, and possibly dangerous. Count how many lumens from one square centimeter of the diffuser your home lamp emits.
Effect of Set on Circadian Rhythms
The production of the sleep hormone melatonin is regulated by a single factor - the blue component of light that enters the eyes. Here is the schedule:
Curve of the impact on the circadian system c (λ). Tapan K. et al. Anatomy of the spectrum for melatonin suppression: evidence for a novel non-rod, non-cone photoreceptor system in humans. Journal Physiology 535 (2001) pp.261-267.
The maximum, as you can see, falls on the blue light. Green and longer waves do not affect the circadian system. For example, the golden light of sodium lamps, which illuminate the roads, illuminates, but does not wake. And incandescent lamps hardly wake up, since there is almost no blue in their warm light.
But daytime cold light, in which there is a lot of blue, suppresses melatonin production effectively. If the windows face the sunny side and the curtains are not drawn, the rise will be early.
The general rule : the higher the color temperature of the light, the colder it is, the more blue components it contains, the higher its biological efficiency, the stronger it affects the circadian system (and the more dangerous it is with a high brightness source!).
And now the main question : is there more blue light in the LED spectrum compared to daylight or fluorescent lamps with an equal color temperature ?!
Let us answer, considering the biological equivalent, that is, the fraction of blue light in a given spectrum in relation to the incandescent light. We will consider the equivalent by analogy with the calculation of the luminous flux, but integrating the spectrum not with the visibility curve, but with the biological efficiency curves c (λ) and B (λ) (the method was introduced by the former president of MKO Wout van Bommel ):
It turns out that:
LED - LEDs, F - luminescent lamps, A - incandescent lamp, D - daylight, MAX and MIN - theoretically possible maximums and minimums of BioEq (for non-existent in nature spectra found by linear programming)
It can be seen that for real light sources the biological effect depends on the color temperature, but does not depend on the nature of the light. And the white light of the LEDs does not differ from the fluorescent or fluorescent white light in its non-visual effect.
Using mathematical modeling methods, one can create spectra from individual thin lines in the right places, which have a multiple or a smaller biological equivalent at the same color temperature. The real spectra that more or less fill the visible range have almost the same biological equivalent, which is proportional only to the color temperature.
And now let us ask ourselves a question - is it even dangerous if even a multiple increase in the biological equivalent? Let's look at the title illustration - Renoir Rowers Breakfast. This picture depicts a scene with illumination of about 5,000 lux in daylight with a color temperature of about 5000 K. The biological effect of this light is ten times higher than the biological effect of any “office” luminaires giving normalized 300 lux at any real color temperature. And the people in the picture, tick, happy.
We are waiting for you at LedForum. And write in the comments questions for professionals! Answers will form the basis of new regulatory documents.
Under the review of the mechanisms of the non-visual action of light: photodamage and effects on the circadian system.
Photodamage:
Electromagnetic wave energy can damage biological tissue. Either a large amount of light, or its concentration on a small area, or illumination with high-energy quanta are dangerous.
')
A lot of artificial light is rare - for reference, offices illuminate at 300 lux and normal ambient light in the middle zone on a sunny day in the shade of 10,000 lux.
To concentrate a lot of light on a small area of the retina is simple - look at a bright object. Bright means a light that emits a lot of light from a small area, such as a filament lamp or a LED. The optical system of the eye will project a bright object onto a proportionally brightly lit part of the retina and - hello discomfort and photodamage. Reversible at low dose and irreversible at high.
The projection of the image of a bright object on a proportionally intensely lit part of the retina.
Dangerous blue component of white light - close on the scale and properties to ultraviolet. The quantum energy is greater, the probability of launching photochemical reactions is higher (ultraviolet itself is not dangerous for the retina, since it is filtered out by the lens).
How dangerous spectral components are spelled out in GOST R IEC 62471-2013 “Lamps and lamp systems. Photobiological safety.
Spectral weighted blue hazard function for retina B (λ) and thermal hazard R (λ)
You can not talk about "R", because for thermal damage you need well a lot of light, the photochemical danger curve "B" is more interesting. Opponents of LED lighting claim that the blue component in the light of LEDs is greater, which means photo danger, other things being equal, is higher. This myth dispel below.
Photodamage of the retina by LED light is a real danger, provided there are high-power discrete LEDs in sight. Subjectively perceived sign of photodamage - discomfort when looking at bright LEDs. Uncomfortable - do not look! And cover the LEDs with a diffuser.
Diffuser reduces the brightness of LEDs by several orders of magnitude. For example, office lamps 60 × 60 cm (area 3,600 cm 2 ) with a typical maximum luminous flux of 3,600 lm fit the standard for brightness of 5000 cd / m2 according to GOST 54350-2011 for ceiling lamps. Convenient ratio - 1 LM per 1 cm 2 .
By analogy, we conclude that a lamp is safe if one square centimeter of a diffuser emits no more than one lumen of luminous flux. If less - the lamp is lightweight and comfortable, if more - bright and uncomfortable, and possibly dangerous. Count how many lumens from one square centimeter of the diffuser your home lamp emits.
Effect of Set on Circadian Rhythms
The production of the sleep hormone melatonin is regulated by a single factor - the blue component of light that enters the eyes. Here is the schedule:
Curve of the impact on the circadian system c (λ). Tapan K. et al. Anatomy of the spectrum for melatonin suppression: evidence for a novel non-rod, non-cone photoreceptor system in humans. Journal Physiology 535 (2001) pp.261-267.
The maximum, as you can see, falls on the blue light. Green and longer waves do not affect the circadian system. For example, the golden light of sodium lamps, which illuminate the roads, illuminates, but does not wake. And incandescent lamps hardly wake up, since there is almost no blue in their warm light.
But daytime cold light, in which there is a lot of blue, suppresses melatonin production effectively. If the windows face the sunny side and the curtains are not drawn, the rise will be early.
The general rule : the higher the color temperature of the light, the colder it is, the more blue components it contains, the higher its biological efficiency, the stronger it affects the circadian system (and the more dangerous it is with a high brightness source!).
And now the main question : is there more blue light in the LED spectrum compared to daylight or fluorescent lamps with an equal color temperature ?!
Let us answer, considering the biological equivalent, that is, the fraction of blue light in a given spectrum in relation to the incandescent light. We will consider the equivalent by analogy with the calculation of the luminous flux, but integrating the spectrum not with the visibility curve, but with the biological efficiency curves c (λ) and B (λ) (the method was introduced by the former president of MKO Wout van Bommel ):
It turns out that:
LED - LEDs, F - luminescent lamps, A - incandescent lamp, D - daylight, MAX and MIN - theoretically possible maximums and minimums of BioEq (for non-existent in nature spectra found by linear programming)
It can be seen that for real light sources the biological effect depends on the color temperature, but does not depend on the nature of the light. And the white light of the LEDs does not differ from the fluorescent or fluorescent white light in its non-visual effect.
Using mathematical modeling methods, one can create spectra from individual thin lines in the right places, which have a multiple or a smaller biological equivalent at the same color temperature. The real spectra that more or less fill the visible range have almost the same biological equivalent, which is proportional only to the color temperature.
And now let us ask ourselves a question - is it even dangerous if even a multiple increase in the biological equivalent? Let's look at the title illustration - Renoir Rowers Breakfast. This picture depicts a scene with illumination of about 5,000 lux in daylight with a color temperature of about 5000 K. The biological effect of this light is ten times higher than the biological effect of any “office” luminaires giving normalized 300 lux at any real color temperature. And the people in the picture, tick, happy.
We are waiting for you at LedForum. And write in the comments questions for professionals! Answers will form the basis of new regulatory documents.
Source: https://habr.com/ru/post/368875/
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