Glasses for vision with anti-reflective coating. What is anti-reflective coating. How to choose anti-glare glasses for work and life

Neva Max coating is an innovative breakthrough of the team of researchers and developers of the famous French company BBGR. It has been specifically designed to prevent the formation of minor scratches that inevitably occur with daily wear of glasses.

The composition of the coating "Neva Max" introduced an additional exclusive layer that provides unsurpassed strength characteristics of the lens.

REINFORCING LAYER

Spectacle lenses made of polymeric materials resist mechanical damage well, which is the reason for the high safety when wearing glasses with polymer lenses. However, when worn, their relative disadvantage affects: they are quickly scratched due to the softness of the lens material. Scratches, of course, worsen not only the cosmetic, but also the optical properties of glasses and shorten their service life. To increase the resistance of the surface of organic lenses to scratches, you can use a hard coating on the lenses. Such a coating, without changing the optical qualities of the spectacle lens, increases the resistance of its surfaces to scratches.

Because minerals significantly more resistant to scratching than organic lenses, a thin layer of mineral material (quartz) was applied to the surface of the polymer lens. For the first time, quartz coatings appeared in the early 70s of the last century, but by the middle of the same decade it became clear that this was not best way out out of position. The quartz coating easily peeled off due to the low strength of the connection between the reinforcing layer and the polymer, in addition, the difference in the coefficients of thermal expansion - small for quartz and significant for the polymer base - had an effect. Therefore, even those small temperature differences that goggles are exposed to during everyday use, very quickly destroyed the quartz coating. In addition, scratches that appeared on the surface of the lens under strong mechanical stress had torn edges and were very noticeable.

The mechanism of destruction of a hardening quartz coating can be demonstrated by the example given: if a lens made of a polymeric material with a hardening coating on both surfaces is bent, then one surface of the lens experiences tension, and the other, compression - both coatings experience breaking stress.

The next invention turned out to be more successful - flexibility began to resist strength. An organosilicon compound, polysiloxane varnish, was applied to the surface of the lens. Polysiloxane lacquer has a high elasticity, thanks to which it creates a surface that is not damaged by contact with abrasive particles. After complete polymerization of the varnish, the surface of the spectacle lens becomes highly resistant to scratching. The high elasticity of the lacquer layer allows it to bend along with the lens material during temperature changes, while remaining firmly connected to its surface.

The process of hardening lenses consists of several stages. To ensure that the coating does not have defects, the room where the coating is applied is ensured by absolute cleanliness and complete dedusting of the air. It is very important to carefully prepare the lens surface. First, the lens surface is thoroughly cleaned by rinsing in baths with various cleaning and degreasing chemicals, then the lenses are washed in an ultrasonic bath. After that, the lenses are fixed in a special device that controls the coating process, and are immersed in a bath of liquid polysiloxane varnish.

Preservation of good optical properties of a spectacle lens on which a hardening coating is applied is possible only when the thickness of the coating is the same over the entire surface of the lens. The uniformity of the coating is ensured by maintaining a constant viscosity of the varnish and the speed of dipping and removing the lenses from the liquid varnish bath. This is monitored by high-precision computer-controlled measuring instruments. After being removed from the bath, the lenses are heated for three to four hours. The duration of heating depends on the material from which the lens is made. During this heat treatment the polymerization of the lacquer ends and the strength of the bond between the coating and the lens surface increases.

ENLIGHTENING OF OPTICAL LENSES

A ray of light passing through a transparent medium at some angle different indicators refraction, undergoes certain changes at the interface between the media. One part of the beam will pass inside the second medium, changing its direction. The other part will bounce off the interface, returning to the first medium. In this case, the ratio of transmitted and reflected light is not the same. The proportion of reflected light is mainly determined by the ratio of the refractive indices of the first and second medium and the angle of incidence of the light beam on the interface.

Thus, the surface of any transparent object with a refractive index different from that of air reflects some of the light falling on it. Spectacle lenses are no exception to this rule. Light reflected from surfaces spectacle lenses, does not get into the eyes, therefore, does not participate in the construction of the image on the retina. As a result, the image seen through the glasses is less bright and has less contrast.

But the loss of light is not the only trouble associated with reflection from a spectacle lens. Reflection of light also occurs when light exits the spectacle lens into the air, so the reflection can be multiple. The spectacle lens has a convex surface, that is, in its shape it resembles a curved mirror, which not only reflects, but also distorts the reflection. This distorted reflection is superimposed on the main image seen by the patient through glasses. Since the proportion of reflected light is small, the distorted image is usually very weak, it is practically not perceived by the patient. And yet this image makes it difficult for the eyes and hastens the onset of visual fatigue.

Reflections from the back of a spectacle lens are also a problem. Objects located behind the patient, reflected from the back surface of the lenses, may appear to be located in front of the eyes, disrupting the normal orientation in space. Reflections from spectacle lenses are especially troublesome if light sources enter the patient's field of vision. Due to their high brightness, they give bright reflections, which significantly complicate the work of the eyes. AT most drivers suffer from this phenomenon (blinding by the headlights of oncoming cars), people forced to work under artificial lighting and people working at video monitors.

The principle of operation of antireflection coatings is to create conditions for the interference of light rays incident on the lens and reflected from it. Interference occurs due to the deposition of one or more thin films of various thicknesses on the surface of the lens. transparent materials with different refractive indices. The thickness of the films is commensurate with the wavelength of light. The interference of light reflected from the front and rear boundaries of the antireflection films leads to mutual cancellation of the reflected light waves. The redistribution of the energy of the interfering rays enhances the intensity of the transmitted light. The effect of enlightenment will be maximum if, at an angle of incidence of the rays close to normal, the thickness of the thin film will be equal to an odd number of quarters of the wavelength of the light. Those. The fraction of light reflected by a lens can be significantly reduced by applying a special coating to both of its surfaces. In domestic terminology, such a coating is called an antireflection coating, in the English literature it is called an "anti-reflex" or "anti-reflective" coating that eliminates reflections and light glare. Yet more correct name it should be recognized as domestic - in addition to reducing reflection and eliminating glare on surfaces, the coating makes the lens more transparent, and the image obtained with its help is of higher quality.

We conclude that anti-reflective coating allows the lens to let in more light. About 7.8% of the light is reflected from both surfaces of the lens without anti-reflection coating with a refractive index of 1.5. A lens made of a material with a refractive index of 1.9 reflects 18% of the light. A high-quality anti-reflective coating can reduce reflected light to less than 1%. Thus, if there is an antireflection coating on the lens, more light is involved in the construction of the image on the retina, the image is brighter and more contrast. Subjectively, this is perceived by the patient as an increase in the clarity of the image seen through glasses with anti-reflective lenses. In addition, anti-reflective coatings prevent reflections from bright light sources located in front of and behind the patient. As a result, the blinding effect of light sources is significantly weakened, vision becomes more comfortable. Lenses with anti-reflective coatings also have cosmetic benefits. Since they do not reflect surrounding objects, the eyes of a person wearing glasses are clearly visible through them. This contributes to better visual contact when communicating. Due to the absence of reflections, the lenses look completely transparent, and glasses with coated lenses are almost invisible on the face.

At present, spectacle lenses with one-, two-, three- and multi-layer antireflection coatings are produced. Coatings with multiple layers reduce the reflection of most waves across the entire visible spectrum, as well as rays that strike the lens at various angles. In general, the more layers in an AR coating, the more effective it is.

The color of the anti-reflective coating is visible in reflected light, so if the coating transmits red and Blue colour well, it looks green. If it is blue, then longer wavelengths (green, red, etc.) are transmitted. High performance coatings have a low residual reflection of neutral tones. A bright residual reflection is typical of low-quality, inefficient antireflection coatings. Since not all antireflection coatings equally suppress reflected light, the problem of assessing their quality arises. However, it is not possible to quantify the effectiveness of a coating visually or with instruments commonly found in an optical shop. In this matter, one has to rely on the reputation of the lens manufacturer and the information provided by the company.

The technology of applying antireflection coatings is quite complicated. The most common now are vacuum and chemical methods coatings. Chemical methods compared to vacuum methods, do not require expensive equipment and are more economical when obtaining the simplest types of coatings. Unfortunately, chemical methods do not allow applying antireflective coatings of proper quality to lenses. A highly effective coating can only be created in a vacuum chamber.

Since the coating possibilities are also determined by the properties of the lens material, for each material it is necessary to create its own coating and develop a separate technological process its application.

First, the lens surface is thoroughly cleaned by rinsing in several baths with various cleaning and degreasing chemicals, then washed in an ultrasonic bath. After that, the lenses on a special stand are placed in a sealed chamber of the installation, in which a vacuum is created. A substance heated to a vaporous state is supplied inside the installation, which, settling on the lens, forms the thinnest film. The film thickness is controlled by high-precision measuring devices. On top of the first layer, a second layer is applied, the material of which has a different refractive index. Layers of different thicknesses from materials with different refractive indices alternate. The thickness of the layers is selected, ensuring that the reflection from each layer boundary extinguishes the reflection of light of a certain wavelength from the surface of the lens.

To create a high-strength antireflection coating on the surface of glass lenses, the coating process is carried out at a temperature of about 250°C.

Polymer lenses should not be heated to such high temperatures, so they are coated at a temperature of 80-100°C. Before applying an antireflection coating to a polymer lens, the lens surface is coated with a layer of polysiloxane varnish, which acts as a hardening coating. The elastic lacquer layer prevents damage to the anti-reflective coating during the operation of glasses with anti-reflective lenses.

An anti-reflective coating must be present on lens surfaces with a refractive index greater than 1.5. In addition, the proportion of reflected light increases with oblique incidence of rays. If the light beam forms an angle of 45° with the normal to the surface of the spectacle lens, the reflection loss increases by a factor of 2. To reduce the reflection of oblique rays, multilayer antireflection coatings are also used.

In order for the patient to fully experience the benefits of coated spectacle optics, it is necessary to monitor the cleanliness of the lens surfaces. Proper care behind lenses with anti-reflective coatings will ensure the preservation of their properties for a long time. Lenses should be washed in cool water neutral detergent or use special “sprays” and wipes to clean the lenses. Do not wipe the lenses with paper, as the hard particles it contains can scratch the surface. Polymer lenses should not be subjected to sudden temperature changes and high temperatures (the temperature can reach 80 ° C in saunas, in summer in car interiors left in the sun. Temperature changes can adversely affect the strength of the anti-reflex coating.

WATER-REPELLENT COATINGS

Lenses with anti-reflective coatings allow the eyes to make better use of the light passing through spectacle glasses light, thereby improving the quality of vision. At the same time, a very unpleasant cosmetic defect - reflections from the glass surface - is eliminated. However, sometimes patients complain about the rapid contamination of the coated lenses, while noting that coated lenses when used in the same conditions, they almost do not get dirty. Do anti-reflective coatings really contribute to the rapid contamination of lenses? The answer to this question follows from the very principle of action of antireflection coatings. The most interesting thing is that the consequence of surface contamination clearly demonstrates how significantly the quality of optical surfaces, acquired during antireflection, increases.

The deposition of any substances on the surface of the antireflection coating (water, grease, dust) leads to the fact that in this place the negative interference, which weakens the reflection from the lens, does not occur. After all, the effect of enlightenment affects at a certain refractive index environment, in our case air. Therefore, pollution, replacing the air that is usually adjacent to the lens, deprives the contaminated areas of the surface of all useful properties given to them by enlightenment. As a result, the lens surface is divided into clean areas that have retained antireflex properties, and contaminated areas that do not have such properties. And now, against the background of an almost non-reflective enlightened surface, sections of the “ordinary”, as if not enlightened, lens become clearly visible. Of course, this phenomenon is reversible: washing the lenses completely restores their anti-reflex properties.

Why is the contamination of non-coated lenses not so noticeable? Because their surface is so reflective a large number of light, which against this background, the losses additionally introduced by pollution are almost imperceptible. Thus, both coated and non-coated lenses in the process of wearing glasses get dirty to the same extent. But contamination of coated lenses is more noticeable. And the more effective the anti-reflective coating, the more contaminants on its surface can be noticeable. But even this unpleasant property, albeit easily eliminated by washing, can be eliminated with the help of another one - a hydrophobic (water-repellent) coating applied over antireflection layers. By smoothing out microscopic irregularities on the lens surface, this coating makes it harder for dirt particles to attach to the lens surface. Right choice coating material can provide the following semi-fantastic phenomenon: water drops do not spread over the surface, but roll off the lens, leaving no wet trace behind. What is the reason for such an unusual behavior of water on the surface of the lens? A water drop is made up of individual water molecules. In this drop, the molecules are attracted with some force to each other. The surface of the lens is also molecules, the molecules of the substance that makes up the outermost layer of the lens. If the force of attraction between a molecule of the lens substance and a water molecule is greater than between two water molecules, the water drop will spread over the surface of the lens, tending to turn into thinnest layer one molecule of water thick, acquiring the appearance of a spot. This kind of interaction between liquid and solid called "wetting" or hydrophilicity - water wets the substance that makes up the outer layer of the lens. The force of attraction of water molecules by molecules of glasses and polymers of spectacle lenses more power attraction between water molecules. As a result, all lenses without hydrophobic coatings are wetted by water. Substances used for antireflection coatings are also wetted by water. Therefore, spectacle lenses with coatings and without anti-reflective coatings, without the protection of a water-repellent layer, will quickly become dirty. In the case when the force of attraction between two water molecules is greater than the force with which the lens surface attracts a water molecule, a drop of water tends to take spherical shape. The resulting water ball rolls off the surface without leaving a trace. This type of interaction between a lens and water is called "nonwetting" or hydrophobicity. If a layer of a hydrophobic substance is applied to the surface of a spectacle lens, water droplets can be removed by simply shaking the spectacles. At the same time, after their removal, no spots remain on the spectacle lens.

The wettability of a solid by a liquid is estimated by experts in terms of the contact angle. For non-wetting liquids this angle is obtuse, for wetting liquids it is acute. The larger the contact angle, the more pronounced the water-repellent properties of the hydrophobic coating. What does knowing the value of the contact angle give to the user of glasses? This allows him to compare the effectiveness of various hydrophobic coatings from different manufacturers spectacle lenses. best choice there will always be a coating characterized by the maximum value of the contact angle.

Substances used for hydrophobic (water-repellent) coatings belong to the group of alkylsilanes. Each alkylsilane molecule contains at least one SiO group, which provides a strong connection between the hydrophobic layer and the lens, as well as a hydrocarbon chain that endows the substance with hydrophobic properties. The thickness of the hydrophobic coating is very small. Usually it is no more than 1/10 of the thickness of one antireflection layer, that is, only a few molecules.

Spectacle lenses with hydrophobic coatings have significant advantages. They are more resistant to dirt and stay cleaner longer. This ensures that the user maintains good optical properties of the lenses while wearing glasses. The hydrophobic properties of the lens surface also greatly simplify the care of glasses: the lenses are easily cleaned by wiping with a special cloth. Their surface is easy to dry after washing, while the water does not leave stains on the lenses. Of course, the question arises - but this is about water, and fats, dust? Just a negative property of hydrophobic coatings is a high affinity for fats, which makes it more difficult to remove fatty contaminants from the lens surface. But not always. Many lens manufacturers have their own methods and compositions of coatings, including those with a water-dirt-repellent effect.

Each such coating has its own special name. Therefore, lenses with such a coating are more resistant to fatty contamination, and if necessary, they are easily cleaned of grease.

The technology for obtaining water-dirt-repellent is similar to the technology used for the enlightenment of spectacle lenses. Coating substances are converted into a vapor state. The resulting vapor in the vacuum chamber settles on the lenses, forming a very thin water and dirt-repellent layer.

Despite the economic crisis, the eyewear sector continues to grow, as evidenced by big number innovations from companies. Many world manufacturers of spectacle lenses began to offer coatings that have improved characteristics compared to previous versions of branded coatings, including higher antistatic properties that make spectacle optics products stronger and more durable.

A unique layer is applied to anti-reflective lenses, which has the ability to filter out reflected light fluxes, leaving only a safe sector yellow color. Such eyepieces completely absorb the harmful blue rays. This is very important factor, since it is this sector that has the greatest negative impact to the visual apparatus.

In a world filled with numerous gadgets, people great amount time is spent in front of a computer monitor, not thinking about how tired the eyes are from light reflections. When using protective optics, the negative impact is minimized.

Those who have problems with refraction should consider buying anti-reflective products with diopters. They act as a protective barrier and correct existing deviations.

Indications for the use of anti-reflective lenses

In appearance, the product is no different from ordinary eyepieces with diopters. However, if you look closely, you can see green or blue overflows on the surface. This is due to the fact that the lenses of anti-reflective products are coated with a unique coating that reflects glare - the main reason for the loss of visual acuity when working with a computer. Also, an antistatic layer is applied to the product, so that the lenses do not attract dust particles.

If a person has an ophthalmic problem, he is prescribed anti-reflective lenses with diopters. Of course, the product does not provide 100% protection against negative impact technique, so remember to take regular breaks from work so that your eyes can rest. It is advisable to be distracted from the monitor every hour, the duration of the rest is fifteen minutes.

Doctors also recommend anti-glare glasses in the following cases:

• Regular work with gadgets for a long time;
• Tendency to dryness of the mucous membrane;
• Cutting and burning in the eyes;
• Increased lacrimation;
• Sensation of sand under the eyelids;
• Photophobia;
• Redness of the sclera;
• Chronic fatigue visual apparatus.

The difference between polarized and anti-reflective glasses

Even in specialized salons, these two concepts are often confused. To learn how to distinguish between them, you first need to decide on the definition of glare. These are spots that appear on a smooth or raised, glossy surface that reflects light. Thus, it turns out that any surface can glare (with sufficient illumination and at the right angle of inclination).

Light polarization is a more complex term. It manifests itself when the rays hit the plane at a certain angle, reflected and propagated in the vertical and horizontal direction. The more reflective a surface is, the more damaging glare is to the eyes. Vertical polarization conveys information about the shades of the object and its contrast, while horizontal polarization generates various noises (blind spots, reflections, etc.).

Glare appears regardless of the time of year. Rays can be reflected from the water surface, snow. In conditions of poor visibility (for example, in heavy fog), glare adversely affects visual acuity, since parameters and colors are distorted. The eyes get tired quickly, the person begins to experience discomfort.

Anti-reflective products are a completely different term, since such a surface should not give shine or create glare. Such optics include lenses with a unique coating that makes the visual system transparent. Such eyepieces are often also called enlightened.

Anti-reflective glasses reduce the amount of light reflection from the lenses, while increasing image contrast and visual acuity. If you look at a person in such products, you can easily see his eyes, and not see your own reflection in the glasses.

So let's sum it up. Anti-glare glasses let in more light without forming reflections. Polarized optics have less throughput, but also blocks a variety of interference well.

The principle of operation of anti-glare glasses for a computer

The PC monitor emits the entire "bouquet" of light fluxes, but most of all the blue and violet spectrum. It is these waves that are responsible for the excessive load on the visual apparatus, since they are part of UV radiation. Short rays scatter before reaching the retina of the eye. Thus, clearing the way for green and yellow long-wave streams. For this reason, the picture on the monitor often seems blurry. But red rays are considered useful, because they restore the metabolism in the tissues of the visual apparatus.

Anti-glare glasses block violet and blue light, preventing damage to the retina and lens. These eyepieces protect your eyes from electromagnetic radiation from the PC display, as well as from excessive brightness and glare.

Computer optics is designed to transmit orange and red streams, they have a beneficial effect on the visual apparatus. Also, the products block harmful short-wave impulses. As a result, image contrast and color reproduction are improved.

Anti-reflective lenses reduce drowsiness and increase efficiency by 30%, as the load on the eyes is reduced.

Working principle for drivers

The sun's rays, especially in the summer heat or snowy winter, can lead to an emergency on the road. Since they almost completely blind the person behind the wheel. Some car enthusiasts use regular tinted sunglasses, but they only slightly darken objects in the field of view, without protecting from glare.

For the first time on the market, anti-reflective glasses were released by Polaroid Corporation. Therefore, products this manufacturer considered a classic. Initially, the role of the polarization layer was played by the thinnest plastic film, which was applied to the surface of the lens. The protective coating was located on top of the glass, which caused additional inconvenience, since it was often covered with scratches during transportation.

Modern technology allows you to hide the anti-reflective film inside the lens, which prevents its damage.

After watching the video, you will additional information about optics for drivers with a polarizing effect.

How to choose anti-reflective glasses

When choosing such products, first of all, you should decide for what purposes you plan to use it:

• Glasses with tinted lenses provide maximum protection from UV rays, scattering glare. They also significantly reduce the blinding of drivers by the headlights of oncoming cars. They make it possible to comfortably drive vehicles in the fog and reduce eye strain;
• Yellow lenses block UV, glare and reduce snow glare. They are recommended for use in low light conditions, in fog or on a blinding sunny day;
• Brown eyepieces also block harmful radiation, reduce headlight glare, relieve eye strain and allow you to drive in foggy conditions.

In any case, before buying, you should consult with an ophthalmologist who will help you choose the best option.

Rating of the best

Anti-reflective glasses are presented in a wide range. However, there are several manufacturers that have proven themselves in the market, offering consumers a quality product.

night view clips

The product is used for daily wear. Lenses improve image clarity, brilliance and color contrast. Has high UV protection. The advantages of the products include:

• The use of unique technology to protect the organ of vision;
• 100% UVA/UVB blocking;
• You can read in them, provided that the room is well lit;
• Suitable for people with visual acuity problems;
• Minimize eye fatigue
• While driving, it protects against the blinding headlights of oncoming cars;
• They allow you to see well even at night.

The cost of the product is approximately four hundred rubles.

Visual discomfort caused by regular use of a computer is called computer visual syndrome. It is diagnosed in 70% of people who work in front of a monitor for three or more hours a day. Anti-reflective glasses with regular use will help to avoid the development of myopia, hyperopia and astigmatism.

The effect of monitor radiation on the eyes

The reasons for this phenomenon lie in the peculiarities of the perception of the monitor by the human eye. When we read printed work, text and pictures are sharp, but the monitor includes a lot of flickering pixels. Therefore, the text on the monitor does not seem clear enough to the eye.

Focusing the eye is also difficult because the pixels near the center of the screen are brighter than those located at the edges. This dissonance provokes rapid fatigue. visual system. In addition, vision is affected by the intensity of the glow, font features, the location of information blocks, colors, and even the position of the monitor.

In order to prevent deterioration of vision, you need to constantly follow the rules of working at a computer, monitor your posture and the location of the monitor (60-70 cm from the eyes). Every hour you need to take a break, do gymnastics for the eyes. To avoid drying out of the mucosa, you can use moisturizing drops. For a prescription, you need to contact a specialist.

Using even the most protected and modern monitor, a person still blinks 2-3 times less than usual. This leads to the drying of the cornea and the formation of microcracks. The presence of lesions in the mucosa causes discomfort and over time provokes a decrease in visual function.

Even with a slight deterioration in vision, you need to undergo an examination and find out the cause. If the deterioration is due to computer use, you can purchase special glasses that minimize harm.

The difference between polarized and anti-reflective glasses

It is noteworthy that even in optics salons, these types of optical systems are often confused. In order to understand these concepts, you need to know what glare is. And glare is a spot of light that is observed on a convex or flat glossy surface that reflects light. It turns out that any surface can create glare (at a certain angle, as well as with proper lighting), even the lenses of glasses.

The polarization of light is a more complex concept. It occurs when light hits a surface at a certain angle, is reflected and propagates predominantly horizontally and vertically. Vertical polarization of light conveys information about colors, contrast, and so on to a person, while horizontal polarization creates noise, glare, interference, and blind spots. And the higher the ability of the surface to reflect light, the stronger the glare will affect vision.

Glare occurs at any time of the year. This occurs when light is reflected from snow, water, and even in foggy conditions. In conditions of poor visibility, glare reduces visual acuity by distorting colors, shapes, and contrast. All this provokes eye fatigue and corresponding discomfort.

It is noteworthy that the reduction in light intensity through the use of sunglasses does not reduce glare. To reduce the negative impact of glare from horizontal surfaces, only polarized lenses that have a polaroid coating can be used. The principle of operation of glasses is hidden in a transparent polarizing film that blocks reflected rays.

Polarized glasses eliminate glare and allow you to see the world clearly without damaging the eyes. These glasses are recommended when driving vehicles as bright reflections can dazzle.

Anti-glare glasses are a different concept, since an anti-reflective surface means one that has almost no shine and no glare. It is correct to call anti-reflective those lenses that have a special coating that makes the optical system more transparent. Such glasses are also called enlightened or anti-reflex.

Anti-reflective lenses are designed to transmit light and reduce the reflection of light directly off the glasses. Thus, image contrast and visual acuity are increased. If you look at a person who wears such glasses, you can see his eyes, and not a reflection in the glasses. It turns out that anti-reflective glasses let in more light, without giving reflections, and polarized glasses block reflections, letting in less light.

The principle of operation of anti-glare glasses for a computer

The computer screen emits the entire spectrum of light rays, but mainly violet and blue waves overload vision. They are part ultraviolet radiation. It is also noteworthy that short-wavelength rays are refracted and scattered halfway to the retina, making way for green and yellow long-wavelength rays, and therefore often the image on the screen seems blurry. Interestingly, red rays are very useful, they restore metabolic processes in the eye tissue.

The benefit of anti-reflective computer glasses is that they block violet and blue rays, protecting the retina and lens from ultraviolet radiation. Such optical systems protect the eyes from the electromagnetic radiation of the monitor, as well as glare and excessive brightness.

Computer glasses are designed to let through the red and orange parts of the spectrum, which have a beneficial effect on the organs of vision. They also block shortwave - harmful - rays. Thus, contrast and color perception are increased.

Anti-glare glasses reduce drowsiness and increase efficiency by 30% (by reducing eye strain).

Indications for the use of anti-reflective lenses

In appearance, computer glasses do not differ from conventional optical systems with diopters. However, upon closer inspection, you can see green, blue and purple overflows on the surface of the lenses. This is due to the fact that a filter coating is applied to the glasses of computer glasses, which reflects glare - the cause of reduced vision when working in front of a monitor. Also, computer glasses have an antistatic layer that does not allow the glass to be magnetized.

If the patient has reduced vision, doctors usually prescribe anti-reflective glasses with diopters. It must be remembered that such glasses do not protect the eyes from negative impact completely, so you need to periodically take breaks from working at the computer. To minimize harm from the monitor, it is enough to give your eyes a rest for fifteen minutes every hour. For these purposes, you can install a special program on your computer that will remind you of the need to organize a break.

Computer glasses are shown to those people who spend more than three hours a day in front of the monitor. Similar optical systems are allowed for both adults and children.

Indications for the use of anti-reflective glasses:

• regular and long-term use of equipment with screens (phones, tablets, computers, etc.);
• tendency to dry out mucous;
• feeling of pain or burning;
• tearing;
• photophobia;
• redness;
• chronic eye strain.

Patients note that when wearing anti-reflective glasses, their performance increases due to the fact that eye fatigue is reduced. With use, dryness and burning disappear, as well as pain during overvoltage. It also reduces the frequency of headaches and dizziness.

How to choose anti-glare glasses for work and life

You should always remember that even with minor health problems, it is always better to consult a doctor. Despite the simplicity and safety of anti-reflective glasses, it will be better if they are prescribed by an optometrist. This is due to the fact that during the examination, the doctor can identify a serious deviation and prescribe treatment in time. Pain and redness often accompany inflammation of the eyes.

When choosing anti-reflective glasses, you need to consider the following factors:

1. Frame characteristics. For your own comfort, you need to choose a frame that will fit the shape of the face and the taste of the patient. You also need to make sure that the frame does not put pressure on the bridge of the nose or ears.
2. Image quality. Glasses should not distort the picture, increase or decrease objects, narrow the horizons.

When the patient does not have vision problems, the doctor can prescribe ordinary "pacifiers", the glasses of which will be coated with a protective anti-reflective layer. Anti-reflective lenses are made of plastic and glass. Plastic ones get scratched quite quickly, but they are recommended for children, because they do not break into fragments under pressure and do not injure the eyes.

Types of lenses for anti-reflective glasses:

1. Monofocal. Thanks to such lenses, a normal perception of objects without size distortion is ensured. Such optical systems are suitable for people with normal vision. Their task is to reduce eye fatigue, they prevent the deterioration of vision and even a violation of posture. Thanks to monofocal lenses, headaches and discomfort in the neck disappear. These glasses are most often prescribed to young and old people.
2. Bifocal. These lenses have two optical zones: the upper one is designed for studying objects on the monitor, and the lower one helps to see objects at close range.
3. (progressive). These lenses have three optical zones for different mode work (computer, near, far). These glasses provide the most comfortable use of modern technology.

When choosing glasses, be sure to study the documentation for the product. So you can save yourself from buying a fake, which is quite capable of being harmful to the eyes. The goods of German, Japanese and Swiss manufacturers are recognized as the highest quality. Chinese lenses are less effective and durable, but are sold at an affordable price.

It must be remembered that even the most expensive monitor does not provide eye protection. Therefore, anti-glare glasses will be indispensable for anyone who spends a lot of time in front of a computer or TV. You can always choose a frame that will make glasses not only useful, but also stylish.

Features of anti-glare glasses for drivers

If we talk about drivers, anti-glare glasses help them recover their vision faster after being blinded by the headlights of oncoming cars. However, such lenses (with the addition of diopters) are recommended only for drivers with reduced vision, since in normal vision, any lenses reduce light transmission. Drivers will benefit from polarized lenses that protect against glare, but should not be used at night or in bad weather.

Anti-headlight glasses will be much more effective when driving. They include yellow or yellow-orange lenses that block blue light. These glasses can be used at night and during bad weather, as they increase the contrast of the image.

Given all of the above, we can conclude that all computer users need anti-glare glasses. They will not only save you from discomfort and eye fatigue, but also avoid serious violations vision.

Our expert is a researcher of the laboratory of ophthalmoergonomics and optometry of the Helmholtz Moscow Research Institute of Public Health, Candidate medical sciences Nina Kushnarevich.

Drivers are required to conduct an inspection of their car annually, and an examination of their own vision must be done at least. After all, a long and monotonous load on the eyes, which includes driving a car, can not be the best way to affect the state of the visual apparatus, and sometimes this happens quite quickly.

Optics by the eyes, but not by eye

Is it necessary to say that a "sharp eye" for a driver is the first thing?! Seems obvious! No matter how! You talk to the ophthalmologists and your hair stands on end. It turns out that most of the motorists who turn to them, who have by no means perfect vision, do not even think about the need to wear glasses. Blind-sighted drivers somehow adapted, adapted and feel very confident behind the wheel, ignoring the fact that they have vision problems. But this confidence is deceptive, and you can pay dearly for it. For example, ailments such as retinal dystrophy, damage to the optic nerve, and, of course, refractive errors (even small ones) can lead to a deterioration in the ability to distinguish objects located on the side. What a violation of peripheral vision while driving can lead to is clear to everyone without further ado.

For drivers, the contrast sensitivity of the eyes is also extremely important, which allows you to distinguish between low-contrast images (for example, pedestrians at night), correctly determine the mutual speed of all participants traffic etc. Many have difficulty driving at dusk, in fog. All these problems can be solved with the right glasses or contact lenses.

Glasses or lenses?

Contact lenses are more comfortable. They give less distortion than glasses (especially at high diopters). Therefore, they are preferred for nearsighted people. In addition, any glasses limit peripheral vision because they provide the biggest correction, only when a person looks straight ahead, and not sideways. Another convenience contact lenses- that they are always in the correct position, and the glasses sometimes have to be corrected, which can distract the driver's attention at the most inopportune moment. And in case of injury, the risk of injuring the eyes of a person with lenses, by the way, is also lower than that of a “bespectacled man”.

However, contact lenses also have disadvantages. First of all, it is more high price and more complex care (exception - daily lenses which cannot be reused). In addition, with non-contact vision correction (using glasses), there is no interaction between the lens and the cornea, which is especially important for people with dry eye syndrome, for whom wearing lenses can cause discomfort. In addition, contact lenses should not be worn during illness (including with a common cold), as well as with conjunctivitis, keratitis, and even when taking oral contraceptives. And one more small but significant minus - on a clear, fine day, contact lenses (even those equipped with a UV filter) still cannot replace Sunglasses. The fact is that lenses can protect against harmful effects sunlight (including from reflected and peripheral) only inner part eyes. Wherein eyeball and the skin adjacent to the eye are left unprotected. That is why, when wearing contact lenses, motorists must also use sunglasses.

If points, what kind?

Selected by a doctor. Under no circumstances should you make this choice yourself. This is the business of an ophthalmologist, who should definitely be consulted before obtaining a license and in the coming months after starting to drive. And then - regularly, at least once a year.

with maximum correction.. AT ordinary life a visually impaired person can afford not to wear glasses at all or to wear lenses that are weaker than required, but in a car interior, such “eyepieces” are needed in which vision will be optimal.

well seated. The driver should not have the need to constantly or from time to time adjust glasses moving down on the nose - this distracts from the road and impairs vision. Therefore, you should choose frames with high-quality nose pads and suitable in size. The design of the frame is also important - the temples should be thin so as not to interfere with the view.

Made from durable material. Polymer lenses (plastic, fiberglass) are recommended for drivers, as they are lighter and do not break (the most durable materials are polycarbonate and various combined materials: Trivex, etc.). While polymer lenses can change over time, they are optically as good as glass lenses, which are banned by drivers. However, there are exceptions: the use of special technologies makes it possible to manufacture glass lenses that, breaking on impact, do not crumble into small fragments.

Transparent. Any colored lens will block more light. Therefore, ideally glasses should be transparent. It should be borne in mind that according to international standard ISO 14889 driving lenses with less than 75% light transmission at night are not permitted, regardless of color.

Protectors and saviors

Today you can buy glasses for drivers with special coatings that have various protective properties.

Anti-reflective coatings. Such glasses let in more light and help the eyes recover much faster after being blinded by the headlights of other cars. Therefore, in conditions of poor visibility on the road, they can significantly improve the quality of vision. Typically, these coatings are applied to one or both surfaces of spectacle lenses. However, such glasses are needed only for people with vision problems. For those who see well, there is no need to wear spectacle lenses without diopters with anti-reflective coating, since any lens reduces light transmission.

Polarized lenses. Effectively protect both from the blinding sun, and from the reflected light. Polarizing filters are used both on glasses with diopters and on ordinary sun glasses, which are good during the day, but are categorically unacceptable for driving at night or in poor lighting conditions.

Photochromic glasses ("chameleons"). They differ in that they change color depending on the lighting: they darken in the sun, and become transparent indoors. It is possible to use them while driving, but we must remember that a significant proportion of ultraviolet light is retained by the windshield, which reduces the sun protection effectiveness of such lenses.

Anti-fare glasses (with yellow or yellow-orange lenses that block the blue color of the spectrum). Such glasses are suitable for driving at night and in cloudy weather, as they increase the contrast of the "picture". But the main thing that drivers who drive at dusk should know is that the most accurate correction is needed for night driving. Indeed, in the dark, the pupil expands, which leads to a significant increase in visual interference, and vision (especially contrast sensitivity) becomes worse.

What are eyeglass lens coatings? What are they needed for? And what is a "multi-functional coating"?

The history of glasses goes back over 800 years. Initially, they were made only from glass of different thicknesses and curvatures, but since then science has stepped far forward, and high-tech developments make it possible to make glasses from plastic, applying special coatings to them that improve the quality of the lenses.

tags medicine glasses eyeglass lenses vision Ophthalmology vision correction eye lens coatings

The main types of optical coatings for spectacle lenses

Hardening or abrasion resistant
Functions: prevent scratches that impair the optical properties of polymer lenses.
Hardening coatings, without changing the optical qualities of the spectacle lens, increase its resistance to scratches. They can also be used simultaneously with anti-reflective and hydrophobic coatings.

Enlightening or anti-reflex
Functions: Eliminate glare and reduce eye strain, increasing the comfort of wearing glasses.
Thanks to the anti-reflective coating, the reflection of light from the surface of the lens is reduced and its light transmission is increased. Due to this, the quality of vision and image clarity are improved, visual fatigue is reduced, and the lenses become so transparent that they do not interfere with others to see the beauty of your eyes. Anti-reflex coatings are especially necessary for those who drive in the evening and at night. For the effectiveness of such coatings, they are often applied in several layers.
Read more about anti-reflex coatings.

Water and dirt repellent
Functions: increasing the resistance of the spectacle lens to dirt and facilitating the cleaning of the surface of the spectacle lens from water and dirt.
Water-repellent (or hydrophobic) and dirt-repellent (or lipophobic) coatings have been created to make eyeglasses easier to care for while extending their lifespan.

Multifunctional eyeglass lens coating
Glasses with a multifunctional coating combine the advantages of a hardening, anti-reflection and hydrophobic layers. In other words, they are scratch-resistant, do not glare and get dirty less.

The structure of the multi-coverage includes:
. hardening coating;
. several layers of anti-reflective coating;
. water and dirt repellent coatings.

"Multilayering" allows you to increase the life of the glasses and the comfort of wearing them.
The Ochkarik online store presents spectacle lenses with multifunctional coatings from the world's best manufacturers - Essilor and Seiko.

Other optical coatings for spectacle lenses

The term " multifunctional coating” most often implies the presence of the three above-mentioned layers, but manufacturers are not limited to this.
For example, companies Essilor and Seiko produce glasses with an antistatic coating, which prevents the glasses from dusting and allows you to neutralize static electricity.
There are spectacle lenses with anti-fog coating. It neutralizes the "fog" that forms on the surface of the glasses when the temperature changes.
Special mention should be made of coatings with the function of protecting against dangerous blue-violet light emitted by the screens of electronic devices.
Optical coatings of spectacle lenses solve many problems of spectacle wearers (dirt, scratches, glare, fogging, etc.) and practically do not affect the thickness of the glass, but their main advantage is to improve the properties of spectacle lenses, and hence the quality of vision.