What do we call excessively bright light? The effect of lighting on vision.

Insufficient lighting affects functioning visual apparatus, that is, it determines visual performance on the human psyche, his emotional condition, causes fatigue in the central nervous system resulting from the effort made to recognize clear or ambiguous signals.

It has been established that light, in addition to providing visual perception, affects the nervous optical-vegetative system, the system of formation of immune defense, the growth and development of the body and affects many basic life processes, regulating metabolism and resistance to adverse factors environment. A comparative assessment of natural and artificial lighting based on its effect on performance shows the advantage of natural light.

It is important to note that not only light levels, but all aspects of lighting quality play a role in preventing accidents. It may be mentioned that uneven lighting can create adaptation problems, reducing visibility. When working under poor quality or low levels of lighting, people may experience eye fatigue and fatigue, leading to decreased performance. In some cases, this can lead to headaches. The reasons in many cases are too low levels illumination, glare of light sources and brightness ratio. Headaches can also be caused by pulsating lighting. Thus, it is clear that improper lighting poses a significant threat to the health of workers.

To optimize working conditions it has great importance workplace lighting. The objectives of organizing workplace illumination are as follows: ensuring the visibility of the objects in question, reducing stress and fatigue of the visual organs. Industrial lighting must be uniform and stable, have the correct direction of the light flux, eliminate the glare of light and the formation of sharp shadows.

There are natural, artificial and combined lighting.

Inspection of lighting conditions consists of measurements, visual assessment or calculation of the following indicators:

1. natural light factor;

2. illumination of the working surface;

3. blindness rate;

4. reflected gloss;

5. illumination pulsation coefficient;

6. lighting at workplaces equipped with PCs;

illumination on the screen surface
white field brightness
uneven brightness of the working field
contrast for monochrome mode
spatial unstable image

Irrational artificial lighting may manifest itself in non-compliance with the standards of the following parameters of the light environment: insufficient illumination of the work area, increased pulsation of the light flux (more than 20%), poor spectral composition of light, increased gloss and brightness on the table, keyboard, text, etc. It is known that during prolonged work in low light conditions and in violation of other parameters of the light environment visual perception decreases, myopia develops, eye disease develops, and headaches appear.

Ensuring the requirements of sanitary standards for light environmental factors for workplaces of personnel engaged in visually intense work, and for workplaces in classrooms and auditoriums educational institutions is important factor creation comfortable conditions for the organ of vision.

Among the quality indicators of the light environment, very important is illumination pulsation coefficient (Kp). Illumination pulsation coefficient is a criterion for assessing the depth of fluctuations (changes) in illumination created by a lighting installation over time.

The requirements for the light pulsation coefficient are the most stringent for workstations with a PC - no more than 5%. For other types of work, the requirements for the illumination pulsation coefficient (Kp) are less stringent, but the value of Kp should be no more than 15%. Only for the roughest visual work is a higher value (Kp) allowed, but not more than 20%.

Local lighting (if used) should not create glare on the surface of the screen and increase the illumination of the PC screen by more than 300 lux. Direct and reflected glare from all lighting sources should be limited.

Often the greatest inconvenience for users is the increased reflectivity of monitor screens and low-quality on-screen filters (if they are installed on display screens). This causes additional eye fatigue. To reduce it, in many institutions, users themselves turn off some of the lamps and work with minimal illumination, both at the workplace and on various surfaces.

This type of work should be considered unacceptable, because in this case, the illumination on the retina of the eye from any sign requiring discrimination turns out to be lower than the physiologically necessary value, equal to 6–6.5 lux. The required illumination is adjusted by the pupil size from 2 mm (at very high illumination) to 8 mm (at extremely low illumination for the roughest work). It has been established that the optimal brightness levels of surfaces range from 50 to 500 d/m2. The optimal brightness of the display screen is 75–100 cd/m2. With such screen brightness and table surface brightness within the range of 100–150 cd/m2, the productivity of the visual apparatus is ensured at the level of 80–90%, and the pupil size remains constant throughout acceptable level 3–4 mm.

Therefore, by “fighting” the glare on the display screen in the above manner, users simultaneously create other unfavorable conditions for themselves. In particular, the load on the eye muscles increases significantly. This causes increased fatigue of the visual organ, and subsequently the development of myopia.

In reality, non-compliance with lighting and brightness standards occurs in more than 40% of workplaces. Recommendations for meeting the standards are well known. As a rule, it is enough to install an additional number of lamps and slightly change the orientation of the desktops in relation to the light sources. It can be more difficult to meet the requirements of the standards for the pulsation coefficient (hereinafter referred to as Kp) of illumination.

In most rooms (more than 90%), lighting is carried out using lamps that have conventional electromagnetic ballasts (ballasts), and these lamps are connected to one phase of the network. To find out how organizations comply with the requirements for pulsation coefficient standards, using the Argus-07 lux pulsometer and TKA-PKM, measurements of the pulsation coefficient were carried out at many workplaces and educational places in different organizations (including workplaces with PC).

Our measurements and analysis of literature data show that in terms of the value of Kp, most of the surveyed places did not meet the requirements of the standards: the actual values of Kp in different rooms for different types lamps with fluorescent lamps range from 22 to 65%, which is significantly higher than the norm. Currently widely used ceiling lamps 4x18 W with a mirrored grille have a pulsation coefficient of 38-49%, for this reason many workers find it difficult to force themselves to work on a PC, as they get tired very quickly, sometimes experience dizziness and other discomfort. The pulsation coefficient of incandescent lamps is 9-11%, of ceiling lamps of the “Kososvet” type - 10–13%, but they are less economical.

An increase in the illumination pulsation coefficient Kp reduces a person’s visual performance and increases fatigue. This is especially evident among students, primarily among schoolchildren under 13–14 years of age, when visual system still being formed.

Unfortunately, significant non-compliance is overlooked in many organizations. And in vain. It has been established that actually increased pulsation of illumination has negative impact to the central nervous system, and to a greater extent - directly on the nerve elements of the cerebral cortex and photoreceptor elements of the retina.

Studies carried out at the Ivanovo Research Institute of Occupational Safety and Health have shown that a person’s performance decreases: tension appears in the eyes, fatigue increases, it is more difficult to concentrate on complex work, memory deteriorates, and headache. The negative impact of pulsation increases with increasing depth.

For those who work with a display screen, visual work is the most intense and differs significantly from other types of work. According to the Institute of Higher Education nervous activity and neurophysiology of the USSR Academy of Sciences (RAS of Russia), the brain of a PC user is forced to react extremely negatively to two (or more) simultaneous, but different in frequency and non-multiple rhythms of light stimulation. At the same time, pulsations from images on the display screen and pulsations from lighting installations are superimposed on the biorhythms of the brain.

Methods for reducing the light pulsation coefficient.

There are three main ways:

connection of conventional lamps to different phases three-phase network (two or three lighting fixtures);

power supply of two lamps in a lamp with a shift (one with a lagging current, the other with a leading current), for which compensating ballasts are installed in the lamp;

use of lamps where the lamps must operate from alternating current frequency 400 Hz and higher.

Practice shows that currently in most premises all rows of lamps are connected to one phase of the network, so the implementation of such a technique as “dephasing” lamps is often difficult. Therefore, the most realistic options are often the following:

dismantling previously installed lamps equipped with electromagnetic ballasts and installing in their place new lamps equipped with electromagnetic ballasts (i.e. electronic ballasts);

leave the existing lamps (if they comply with the requirements of clauses 6.6, 6.7 and 6.10 of SanPiN 2.2.2/2.4.1340-03), remove electromagnetic ballasts from them and install electronic ballasts in their place); dismantling ballasts and installing electronic ballasts in one luminaire takes an average of 15 – 20 minutes.

Currently, the leaders in the introduction of luminaires with electronic ballasts are Sweden, Switzerland, Austria, Holland, Germany, then the USA and Japan. The complete transition of all organizations in the world to such lamps in the next 10–15 years will significantly reduce energy consumption in the world, i.e. partially improve the environmental situation.

An excess of bright and harsh visible light can be called "excessive brightness." Sharp, bright light can appear both during the day and at night - in various forms. Not only does it distract your attention, but it can also be dangerous.

The influence of bright light causes eye fatigue from DC voltage, and subsequently, in rare cases, these signs can cause temporary blindness.

Company specialistsTransitionsThere are four categories of excessively bright light:

Distracting light

At night, bright light from street lamps or headlights of an oncoming car is very distracting to the driver. Or, for example, reflection from the front surface of your spectacle lenses (if they are not multi-coated) also contributes to the dispersion of the concentration of vision, and also creates discomfort for the interlocutor, because Your eyes are not visible. In the same way, reflection from inside glasses lenses can cause eye fatigue and loss of concentration.

Uncomfortable light

Normal sunlight also causes discomfort. Each person feels the degree of discomfort from bright light in their own way - regardless of the weather and time of day. This light can come from any light source. Uncomfortable light causes eye strain, causing eye fatigue.

Light that reduces visibility of activities

Intense, bright light shining directly into your face limits your activity and overall field of clear visibility. Bright light reduces the clarity of the image on the retina, thereby deteriorating vision. After interacting with bright light its invisible effects persist for some time after exposure.

Reflective or glare light

Shiny, “polished” surfaces give the effect of glare, for example, snow, water, shop windows. Its effect can lead to deterioration of vision and even to temporary, severe blindness, because it can be quite strong. To avoid glare, use polarized glasses lenses.

Do you experience discomfort in bright* lighting? Has your performance decreased? They will help you spectacle lenses SEIKO Transitions combined with high quality anti-reflective coating. They increase clarity of vision, relieving eye strain and fatigue.

We invite you to try new specialized sun lenses. For example, or.

Light is life. This is 50% of your mood and 75% of the comfort in your home. Light determines a lot: the general atmosphere of the home, health and psychological condition its inhabitants, operational efficiency, the beauty of the interior and even the taste of dinner. Therefore, without proper lighting there cannot be a healthy home.

solar circle

Without the sun, everything dies, even humans. Medical fact- lack of natural light affects our body. Vision suffers - initially the eye is tuned to perceive the rays of the sun, and not the light bulb. Immunity deteriorates - ultraviolet exposure Sun rays not only increase the body’s resistance to all sorts of microbes, but also kill these same microbes. The psyche is shaken - sunlight stimulates the work of the central nervous system, and if there is not enough of it, a person becomes lethargic, passive, prone to despondency, or even simply becomes depressed. And without the sun, our biorhythms go crazy and slow down metabolic processes, total vitamin deficiency begins. Therefore, it is very important to let into the apartment sufficient quantity sun rays and bunnies.

There are certain standards for insolation (exposure to direct rays of the sun) of various rooms. For 2-3 hours a day, the luminary should look out of at least one window 1-3 times room apartment and at least two windows of a 4 or more room apartment. If you don’t get 2-3 hours in a row, then the sun will have to look through your windows for a total of half an hour longer. In this case, at least one period of insolation must be at least 1 hour.

Window design must be approached with all seriousness. After all, this is not only a design element, it must transmit light and protect our home from excessive heat rays.

First of all, attention should be paid to where the windows face.

If they look north and partially east, then only diffused light will penetrate into the rooms. The walls in such rooms should be made light: the light falling on them will be reflected many times and thereby increase the illumination. Curtains, especially thick ones, should be designed so that they can be pulled apart during the day. Only light, maximally transparent tulle fabrics are acceptable as fixed curtains.

If the windows face west or southwest, then you should think about how to rid your home of the scorching sun. You can protect yourself from direct rays by using thick but light curtains, blinds, and sun protection film. Green spaces also protect well from overheating. You just need to remember that you still need ultraviolet light, and leave room in the thicket for the sun.

Until the light bulb

Sunlight is wonderful. But, unfortunately, daylight most Our year is short, and there are many cloudy days. This is where the light of a light bulb comes to the rescue. Artificial lighting - obedient lighting. Kinda Magic wand in our hands, which allows us to achieve a variety of effects. In addition to the main utilitarian function - to defeat the darkness, lamps determine the mood and climate of the room. In addition, it is an integral part of the interior. With the help of light, you can place accents or hide flaws, move walls apart, raise or, conversely, lower the ceiling, divide the room into zones

When creating artificial lighting for your home, you need to remember some rules. Firstly, there must be enough light. The total illumination should be from 15 to 25 W of incandescent lamp power per square meter of area.

Secondly, it must be functional. It is more convenient to watch TV in dim light, and to receive guests in bright light that fills the entire room. In the bedroom, it is preferable to have soft, diffuse lighting, and in the kitchen - bright but uniform.

Thirdly, the light should be comfortable: no sharp transitions from shadow to light, bright surfaces or glare - all this is harmful to vision. It is necessary to avoid open sources that irritate the eyes and tire the psyche. A bright point beam of light is good only in table lamps. It is better to achieve softer light in the room. In this regard, ceiling lamps in the shape of a ball or hemisphere are very successful. They are opaque and break direct rays.

And finally, the lighting must be safe. A crystal chandelier in a nursery or an open light bulb in a bathroom is an unjustified risk. And a lamp hanging too low in the kitchen, which you can’t help but hit with your head, is also an unpleasant thing.

Not only Ilyich's light bulb

Three types of lamps are usually used in apartments: incandescent, halogen and fluorescent (also known as fluorescent lamps).

Incandescent lamps have served us for more than 120 years. Their light, with a spectrum shifted to the infrared region, is considered optimal and very pleasant to perceive by the human eye. But these good old light bulbs have one significant drawback: they do not shine as much as they heat. Approximately 95% of their energy is converted into heat, leaving only 5% for light.

Incandescent lamps can be simple, colored or mirrored. Let's look at the latter in more detail. Such a lamp top part The bulb is covered with a mirror layer, which protects the light bulb from overheating and allows it to work much longer. Mirror lamps shine somewhat brighter than usual, and the matte part of the bulb makes the light more uniform and diffused.

Halogen lamps produce a pleasant white light. They illuminate the room better than an incandescent lamp, and consume much less energy. But halogen lamps are very sensitive to voltage changes. In order for them to work in our reality, you need to buy a personal transformer.

Compared to incandescent lamps, fluorescent lamps can significantly save energy and increase the production of light itself. But they make noise, flicker and quickly tire the eyes and psyche. True, lamps latest generation are already devoid of most of these disadvantages, but constant exposure to fluorescent light is still unpleasant. Such lamps can be successfully built into bookshelves, placed above a desk or in the kitchen above the sink, and in the main lighting, incandescent lamps that are more pleasing to the eye can be preferred.

Home lamp science

There are different types of lamps: ceiling, wall, table and floor. You shouldn’t limit yourself to just one type of lighting: the more variety of lamps you have at your disposal, the more convenient your life will be. Don't be afraid to fill your home with light.

Main lamp, ceiling: aka chandelier

Ceiling lamps come in 4 types. Hanging chandeliers or actual chandeliers. These are traditional lamps that hang on chains, electrical wires or metal rods. Chandeliers are the type of shades that “sit” directly on the ceiling. Chandeliers such as spotlights are rotating lamps with narrowly directed light. And finally, lamps built into suspended ceilings.

The bright ceremonial light of a chandelier - the central source of light in the room - not only creates uniform, rich lighting, but also has a unique psychological property: It brings together all the people in the room. In the living room, dining room, and kitchen, it is better to use ceiling lamps that provide combined light: one part of the light flux goes up to the ceiling, and the other (comparable in size with the first) goes down. For the bedroom, it is better to choose chandeliers whose light softly diffuses throughout the room. In the nursery, the lighting should be uniform and quite bright, but it is better to avoid open, intense light sources.

Ceiling lamps can also act as sources of local lighting. Soffits that cast light within a narrow angle will help highlight, for example, a dining table.

Wall lamp

Wall lamps are called "sconces". As a rule, its light fluxes are directed up or down along the wall, almost parallel to it. Using sconces you can zone a room. You can save a lot of money - why light up the whole room when you can only light up the corner you're in? But, most importantly, sconces allow you to create great amount microcosms on the scale of one apartment - to create each family member their own private space. Just remember that a sconce is not necessarily a pleasant twilight. If you are used to reading under a sconce, then its light should be bright enough.

A floor lamp occupies an intermediate position between table and floor lamps. Although it stands on the floor, it emits light slightly higher - at an average level. A floor lamp is not only a lot of comfort and a pleasant atmosphere. It's also a great way to fill a room with soft, indirect light that encourages relaxation, conversation, or reflection.

Floor lamp

It is very fashionable to have floor mounted lamps. And it's also beautiful. For example, a fireplace illuminated from below. Or an aquarium. Or a luminous path from hall to hall. And, sometimes, this is useful - very often floor lamps are mounted in air humidifiers.

You just need to remember that there is no place for floor lamps in a nursery. Little researchers will definitely try to take it apart. And it must be turned on.

Table lamp

Table lamps perform a variety of tasks: illuminate, illuminate, decorate. But their main function is to help you work. It is especially important to have proper lighting in areas where people do work that requires eyestrain.

The table lamp must be placed so that the light falls from the left (for left-handers - from the right), otherwise the shadow from the hand will interfere. In general, it is better to choose the power of table lamps in the range of 40–60 watts, the distance from the lamp to the table surface should be 40–50 centimeters. It is better if the lamp has a movable visor, which will make it possible to direct the light to workplace. It is desirable that the lampshade is opaque and wide open at the bottom, with a large, uniform flow of light.

Sufficient illumination of a sheet of whatman paper when drawing is provided by a table lamp with an incandescent light bulb with a power of 150 watts at a distance of 80–100 centimeters. It is better to knit, embroider, and darn with black threads at 100 watts at a distance of 20–30 centimeters, and to read at 60 watts.

You should not skimp on the quality of a table lamp - damaged eyesight will cost more.

Our site about flylady, home and diets recommends more articles:

In fashion all over the world healthy image life, respect for nature and savings natural resources. Modern technologies are already struggling to keep up with the demands of society and, in an effort to save energy and our vision, the industry is producing more and more new types of lamps.

For example, housekeepers consume several times less electricity, serve better, but in Lately Discussions began about their effect on vision, although it was revealed that if they do not bring benefit, then there is practically no harm from them.

What should healthy lighting be like in the home, in stores and at work? You should not select chandeliers and lamps only according to technical specifications. Light affects not only appearance interior, but also on your attitude and visual acuity.

Properly selected light in the bedroom gives peace and a sense of peace when you need to relax. In the room where you work, lighting should not tire your eyes. Hang cascade chandeliers in it with fairly bright, but not blinding, bulbs.

When choosing a lamp, you need to take into account the size and height of the room. And if the room is small, then it makes sense to hang sconces on the walls in addition to the chandelier; besides, doctors say that such light is more useful.

Previously, incandescent lamps were the most common. Their spectrum is very different from the natural one, since it is dominated by red and yellow. At the same time necessary person There is no ultraviolet in incandescent lamps.

Later developed luminescent light sources helped solve the problem of light starvation. Their efficiency is much higher than incandescent lamps, and their service life is longer. Doctors advise using ceiling lights with fluorescent lamps, the light of which is much healthier than traditional lamps.

Nowadays LED lamps are gaining popularity, but it is still not clear whether they are beneficial or harmful to vision. Some LED lamp designs use a blue LED that emits waves with properties similar to ultraviolet light. This radiation can have Negative influence to the retina of the eye.

But there is still debate on this issue and we can say for sure that the efficiency of such lamps is many times higher than classical lighting. Even if broken, LEDs do not pose a danger to humans, since they do not contain toxic substances. In addition, these lamps do not heat the air, which means the fire hazard factor is completely eliminated.

Are LED lamps harmful to health? Reviews from experts

The massive appearance of LED lamps on the shelves of hardware stores, visually reminiscent of an incandescent lamp (base E14, E27), has led to additional questions among the population about the advisability of their use.

Research centers, in turn, put forward theories and present facts indicating the dangers of LED lamps. How far lighting technology has come, and what is hidden back side medals called "LED lighting".

What's true and what's fiction

Several years of using LED lamps allowed scientists to draw the first conclusions about their true effectiveness and safety. It turned out that such bright light sources as LED lamps also have their “dark sides”.

In search of a compromise solution, you will have to become more familiar with LED lamps. The design contains harmful substances. To make sure that an LED lamp is environmentally friendly, just remember what parts it consists of.

Its body is made of plastic and a steel base. In powerful samples, a radiator made of aluminum alloy is located around the circumference. A printed circuit board with light-emitting diodes and radio driver components are fixed under the bulb.

Unlike energy-saving fluorescent lamps, the bulb with LEDs is not sealed or filled with gas. According to availability harmful substances, LED lamps can be put in the same category as most electronic devices without batteries.

Safe operation is a significant advantage of innovative light sources.

White LED light is harmful to your eyesight

When going shopping for LED lamps, you need to pay attention to the color temperature. The higher it is, the greater the intensity of radiation in the blue and cyan spectrum.

The retina of the eye is most sensitive to blue light, which over long-term repeated exposure leads to its degradation. Cold white light is especially harmful to children's eyes, whose structure is still developing.

To reduce visual irritation, it is recommended to include low-power incandescent lamps (40 - 60 W) in lamps with two or more sockets, as well as use LED lamps that emit warm white light.

Flicker strongly

The harm of pulsations from any artificial light source has long been proven. Flickers with a frequency of 8 to 300 Hz negatively affect the nervous system. Both visible and invisible pulsations penetrate through the organs of vision into the brain and contribute to poor health.

LED lamps are no exception. However, it's not all bad. If the driver output voltage additionally undergoes high-quality filtering, getting rid of the variable component, then the ripple value will not exceed 1%.

The ripple coefficient (Kp) of lamps that have a built-in switching power supply does not exceed 10%, which satisfies sanitary standards. The price of a lighting device with a high-quality driver cannot be low, and its manufacturer must be a well-known brand.

Suppress melatonin secretion

Melatonin is a hormone responsible for sleep frequency and regulation circadian rhythm. IN healthy body its concentration increases with the onset of darkness and causes drowsiness.

When working at night, a person is exposed to various harmful factors, including lighting.

As a result of repeated studies, the negative impact of LED light at night on human vision has been proven. Therefore, with the onset of darkness, you should avoid bright LED radiation, especially in bedrooms.

Lack of sleep after prolonged viewing of LED TV (monitor) is also explained by a decrease in melatonin production. Systematic exposure to the blue spectrum at night provokes insomnia.

In addition to regulating sleep, melatonin neutralizes oxidative processes, which means it slows down aging.

Emit a lot of light in the infrared and ultraviolet range

To understand this statement, you need to analyze two methods of producing white light based on LEDs. The first method involves placing three crystals in one case - blue, green and red.

The wavelength they emit does not extend beyond the visible spectrum. Consequently, such LEDs do not generate luminous flux in the infrared and ultraviolet range.

To obtain white light in the second way, a phosphor is applied to the surface of a blue LED, which generates a luminous flux with a predominant yellow spectrum. As a result of mixing them, you can get different shades of white.

The presence of UV radiation in this technology is negligible and safe for humans. The intensity of IR radiation at the beginning of the long-wave range does not exceed 15%, which is disproportionately low with the same value for an incandescent lamp.

The talk about applying a phosphor to an ultraviolet LED instead of a blue LED is not unfounded. But for now, producing white light using this method is expensive, has low efficiency and many technological problems. Therefore, white lamps based on UV LEDs have not yet reached industrial scale.

Have harmful electromagnetic radiation

The high-frequency driver module is the most powerful source of electromagnetic radiation in an LED lamp. RF pulses emitted by the driver can affect operation and degrade transmitted signal radio receivers, WIFI transmitters located in close proximity.

But the harm from the electromagnetic flux of an LED lamp to humans is several orders of magnitude less than the harm from mobile phone, microwave oven or WIFI router. Therefore, the influence of electromagnetic radiation from LED lamps with a pulse driver can be neglected.

Cheap Chinese light bulbs are harmless to health

Regarding Chinese LED lamps, it is generally accepted that cheap means poor quality. And unfortunately, this is true. Analyzing the product in stores, it can be noted that all LED lamps whose cost is minimal have a low-quality voltage conversion module.

Inside such lamps, instead of a driver, a transformerless power supply unit (BP) with a polar capacitor is installed to neutralize the alternating component. Due to its small capacity, the capacitor copes with its assigned function only partially. As a result, the pulsation coefficient can reach up to 60%, which can negatively affect a person’s vision and health in general.

There are two ways to minimize the harm from such LED lamps. The first involves replacing the electrolyte with an analogue with a capacity of about 470 uF (if free space inside the case allows).

Such lamps can be used in the corridor, toilet and other rooms with low visual stress. The second is more expensive and involves replacing a low-quality power supply with a driver with a pulse converter. But anyway for lighting living rooms and jobs, it is better not to buy cheap products from China.

On the role of illumination for vision. Which light is best for the eyes? Where should I place the TV and computer in the room? How does low light harm your eyes?

Most often, to my question: “Are the child’s books or notebooks sufficiently illuminated while working with them?”, you confidently give a positive answer.
What does a person mean by the concept of “good lighting”?
Some believe that when reading literature, an overhead light provides sufficient illumination of the room, while others require table lamps. Some people choose regular incandescent lamps, others prefer fluorescent lamps. Who is close to the truth? In the vast majority of cases, doctors do not pay enough attention to the lighting characteristics of the rooms in which their patients work and study. Considering that the concepts of “eye” and “light” are inseparable, the doctor at the appointment is obliged to tell parents in sufficient detail about everything related to illumination, its power, the design of lamps and preferences when choosing them.
In what units is illumination measured, what lamp should be chosen to achieve good level lighting?
The optimal illumination for a book or notebook is obtained from a 75-watt incandescent lamp. This corresponds to 150 lux. If you have a fluorescent lamp, then the illumination should be equal to 300 lux.
And if the illumination is higher than specified, will it harm the eyes? Still, the optimal illumination is the illumination I indicated. If, from time to time, the illumination levels are higher, this is not dangerous, given that the illumination of a book on the street in bright sunny weather reaches 100,000 lux.
The question is often asked: What is more dangerous, too much light or not enough?
You don’t have to worry about redundancy; much more often in life we are faced with the most unpleasant fact - under-illumination. It is worth remembering that if you lower the required illumination by half, the muscular system of the eyes strains 8 times more. And therefore, it is not so important what kind of lighting is used: artificial or natural, incandescent or fluorescent. The important thing is that this light is not enough in principle. And then what is the point of treating the same myopia, accommodation spasm, amblyopia, which we talked about in previous classes, if a child who has improved his vision again plunges into an insufficiently lit environment. Optical discomfort arises again, a spasm of accommodation is formed again, and conditions for the progression of myopia are again created. And for those who do not yet have it, conditions appear for it to arise.
Frequently asked question: which lamps are better - incandescent or fluorescent?
The advantage lies with fluorescent lamps, the so-called fluorescent lamps. This advantage lies in the fact that the radiation of such lamps is much closer to the natural spectrum sunlight than incandescent lamps. The only drawback that fluorescent lamps may have is flickering. However, in last years the design of these lamps eliminates this phenomenon. If you have a fluorescent lamp, you should know the rule: look at it with peripheral vision, i.e. fix your gaze not on the lamp itself, but nearby, since it is the periphery of the retina that reacts to flickering. And if you do not feel flickering with your peripheral vision, then the lamp is suitable for lighting. If you feel flickering in your peripheral vision, replace the lamp immediately.
Frequently asked question: Doctor, if you are talking about sufficient lighting for a book or notebook, then tell me, do you need to turn on the general light?
Necessary, since the retina does not like constant contrasts. This also applies to the room where the TV is located, that is, you should never watch TV in a dark room. The general light should always be on. At the same time, it is unacceptable for a lamp, whether ceiling or wall, to be reflected on the TV screen.
How can I check this?
It’s very simple, turn off the TV, turn on the lights, and if they are reflected, and you see them reflected on the screen, then either turn it around or move the light, preventing this reflection phenomenon. This, by the way, also applies to the monitor screen, which we described colorfully and in detail in our publication “Computer Ergonomics”.