What are the best photochromic lenses for glasses? Photochromic lenses. Gentle eye protection

Glasses with photochromic lenses are often called chameleons because they change color depending on the light. Indoors or at night, photochromic lenses are no different from ordinary colorless ones. spectacle lenses or have slight initial tinting.

On the street, such glasses darken themselves, practically turning into sunlight in sunscreens. If you go into the room, then photochromic glasses become transparent again.

How do photochromic lenses work?

These properties of chameleon glasses are explained by the presence of special photochromic substances in the lenses. Under the influence of UV radiation, their spatial structure changes, and they stop transmitting light and the lens darkens. In the absence of ultraviolet light, the opposite changes occur and the lens becomes transparent again.

Previously, the speed of darkening of photochromic lenses depended not only on the degree of illumination, but also on the ambient temperature. In the cold, darkening occurred more quickly than at very high temperatures. So on a very hot summer day the lenses might not reach maximum darkness.

With photochromic lenses produced using the most modern technologies, the speed of darkening and clearing processes and the degree of darkening depend much less on the influence of ambient temperature.

Manufacturing technologies

Photochromic lenses in a darkened state, as a rule, come in two shades - gray and brown, and the degree of maximum darkening can also vary: from weak darkening (10-15%) to strong darkening (80-85%).

Photochromic lenses are produced using various technologies. For example, using Transitions technology, photochromic substances are evenly distributed over the surface of the lens to a certain depth. Many well-known companies- manufacturers of spectacle lenses, such as Essilor, Hoya, Sola, Zeiss, Seiko, produce photochromic lenses using this technology.

According to SunSensors technology, photochromic substances are distributed throughout the material from which the lens is made; such lenses are also called volume-colored. And also a number of companies use this method to manufacture their photochromic lenses.

Hoya, Rodenstock and Kodak produce spectacle lenses from their own polymers with a photochromic agent distributed throughout the mass.

Benefits of photochromic lenses

Photochromic glasses are ideal for people with poor eyesight. Such people usually have to either purchase prescription sunglasses and, when going out into bright light, change their glasses or wear tinted glasses. Chameleons replace two pairs of glasses: regular glasses + sunglasses with diopters.

Chameleons replace two pairs of glasses: regular and sunglasses with diopters

Photochromic lenses do not darken in a glassed room, since glass does not transmit ultraviolet radiation, so photochromic glasses also “do not work” in a car. However, recently, some well-known companies have begun to produce photochromic lenses, which are capable of darkening not only under the influence of ultraviolet, but also when exposed to short-wave blue rays of the solar spectrum penetrating into the interior of the car.

Thus, drivers who wear glasses for vision correction, and in sunny weather must either use sunglasses with diopters or use special clip-on attachments for glasses, have the opportunity to comfortably drive a car in any weather without thinking about changing glasses.

In addition to the fact that photochromes protect 100% from harmful ultraviolet radiation, they provide the light transmission necessary for the eyes, reacting to changes in outdoor lighting, while reducing eye strain, visual fatigue, and increasing the contrast of vision. This is especially important for those who have developed photophobia or increased tear production.

In addition to visual comfort and convenience, photochromic glasses also have medical indications: as an alternative to sunglasses, they are recommended for patients suffering from degenerative diseases of the retina and reduce the risk of developing cataracts.

Photochromic lenses can be either mineral or polymer, including polycarbonate. You can also choose almost any refractive index for your photochromic glasses, making them more subtle if necessary.

Photochromic lenses can be coated with a multifunctional coating that gives the glasses the properties you need. Modern photochromic glasses are available in any design: traditional monofocal, aspherical design, progressive.

Photochromic spectacle lenses are very popular among buyers who want to have glasses that not only provide high vision, but also reliable protection from solar radiation.

How is photochromism used in optics? What are chameleon glasses? What are their advantages?

A person indoors wearing transparent glasses reads or looks into the distance, and when he goes outside, the lenses instantly become dark and protect his eyes from the sun. Magic? Not at all! Elementary photochromism.

Tags medicine glasses glasses lenses vision vision correction lens coatings

Smart molecules

The phenomenon of photochromism is based on the ability of the molecules of certain substances (for example, silver and copper) to change their structure under the influence of ultraviolet radiation. In their initial state, these molecules have a high degree of light transmittance (the glasses are transparent), but as soon as UV rays hit them, they are activated and transmit much less light (the glasses become gray or brown). If the sun disappears, the molecules return to their original state, and the glasses again turn colorless.

It's comfortable. Firstly, vision correction occurs continuously. Secondly, you don’t need to take off your glasses and put on sunglasses when going outside, and do the reverse process when going indoors.

The phenomenon of photochromism was discovered at the end of the 18th century. In the twentieth century, not only physicists, but also manufacturers of spectacle lenses became interested in it.

In 1964, Corning Glass Works released the first photochromic-coated lenses, Photolite. These were glasses with glass lenses on which silver and copper halides were applied. In the 1980s, photochromic coatings began to be applied to organic lenses.

But the real “revolution” occurred in 1991, when PPG Industries and Essilor International merged (Transitions Optical) and jointly developed Transitions technology. This technology has become one of the most popular.

Glass or plastic - what to choose?

Mineral (glass) and organic (plastic) photochromic lenses differ in the production method and some properties. Therefore, the question often arises - which is better?

In glasses with mineral lenses, the photochromic elements are “inside” - they are added when the glass is melted. On organic lenses, photochromic molecules are usually applied “on top”.

In terms of properties, modern inorganic and organic lenses with photochromic coating are practically indistinguishable from each other. However, polymer spectacle lenses “darken” more evenly; in mineral lenses, darkening sometimes “accumulates” along the edges or in the center of the lenses.

In principle, it is not so important what material the glasses are made of - lenses with photochromic coating will in any case protect the eyes from ultraviolet radiation.

Alone instead of a couple

Many people choose glasses with photochromic coating, believing that they will replace prescription glasses and sunglasses. This is true if you alternate between being indoors and outdoors.

Depending on the type of photochromic lenses, they can provide up to 90% darkness, which means they are, in principle, suitable for wearing on the beach. However, most often photochromic lenses are inserted into frames for permanent wear, which are smaller in size than the frames of beach glasses. But this is a matter of aesthetics and personal preference.

The “behavior” of photochromic lenses depends on the air temperature: they darken in the heat, but more slowly and less; in cold weather, on the contrary, the darkening occurs more intensely.

Manufacturers of spectacle lenses are actively working to improve photochromic coatings. Over a million chameleon glasses are sold annually, and demand is only growing. Photochromic lenses are emerging for people who spend a lot of time driving or outdoors, in bright sunshine and at high temperatures. These lenses provide greater darkness and maintain it in hot weather.

There are also lighter photochromic lenses for people who spend a lot of time indoors. Tinted photochromic lenses and lenses with unusual curves are appearing for fashionable frames.

Overall, it is now easy to find photochromic lenses that will suit your lifestyle and the frames you want to wear. And modern coatings will help protect your eyes from UV rays and bright light.

Age-related decline in the quality of vision is an inevitable process, but this does not mean that such changes should be accepted. It is indeed impossible to completely prevent physiological changes, but you can smooth out the symptoms. To correct vision, doctors prescribe glasses with special lenses for farsightedness or myopia. Find out what materials they are made from, how to choose the right one, and whether it’s worth buying options with different coatings.

How to choose the right lenses for glasses

Before you go to the optician, you need to visit an ophthalmologist and undergo a full examination, especially if you are choosing this accessory for the first time. An ophthalmologist will examine refraction, measure corneal curvature, pupillary reactions, intraocular pressure, and conduct an examination fundus and after that he will put accurate diagnosis. You should not save time on going to the doctor, because even the slightest deviation in the prescription will doom you to the wrong purchase and lead to unnecessary financial expenses.

After the doctor has written a prescription, you can go to the optician. The frame can be metal or plastic. The first ones are the most highly durable and less susceptible to deformation, but they make the glasses heavier and can cause allergies. Plastic options are not as massive, but are inferior in strength. The ideal option is metal temples and plastic temples. It would be good if there were silicone pads on the nose pads.

Refractive index

The choice of the base of glasses is carried out according to several indicators at once, one of the most important is the refractive index. It determines the ability of glasses to pass Sun rays. The higher this indicator, the thinner, lighter and more expensive the lenses will be. High index elements reflect 50% more light than their low index counterparts. They provide maximum efficiency and often feature an aspherical design.

When focusing on the refractive index, it is worth taking into account individual characteristics, doctor’s advice and frame material. According to the refractive index and modification of the lenses, they are distinguished:

The only disadvantage of highly indexed glasses is the low dyspepsia coefficient; such lenses cause severe color distortions. Light passing through the polymer is decomposed into several components, which can cause iridescent distortions at the edges, which in medicine are called chromatic aberration. The lower the dyspepsia factor, the more colored spots you will see around objects.

Optical zone selection

The next type of classification is the optical zone. It characterizes how many tricks the glasses have. There are three main types:

• Afocal. They do not have an optical zone and are prescribed by doctors only if there is no need to correct vision. Afocal options are installed in sunglasses, computer glasses, fashion glasses or office glasses.
• Single vision. They can provide vision correction either near or far. The entire surface of such glass has the same number of diopters. Single vision glasses are prescribed to elderly patients to correct poor accommodation.
• Multifocal. The surface of such glass is divided into zones with different diopters. Multifocal elements help you focus your gaze at different distances.

Lens shape

Modern production technologies make it possible to develop lenses not only with a high refractive index and different optical zones, but also of various geometric shapes. The shape affects the thickness, lightness of the frame, the aesthetic appearance of a person, and the brightness of peripheral vision. Based on their shape, lenses are divided into:

• stigmatic or spherical;
• astigmatic or aspherical;
• bifocal or biaspherical;
• progressive or trifocal.

Stigmatic form

This is one of the most popular designs - convex. The spherical shape is inexpensive and suitable for almost any occasion. The surface of such glasses is marked point by point with identical diopters and has an equal radius of curvature. The spherical elements provide high-quality vision only in the central part, the curved side gives a distorted view to the sides. There are two types of stigmatic form:

• biconvex – for correction of farsightedness;
• biconcave – to correct myopia.

Astigmatic

These are lenses in which one or two surfaces are non-spherical. Thanks to this geometric feature, they have minimal optical distortion of objects. When wearing aspherically shaped accessories, a distortion in the size of the eyes may occur. Disadvantages include multiple reflections that appear on the surface of the glass, which is why they are often produced with a special anti-reflective coating. Astigmatic type is prescribed to people with a high degree of myopia or farsightedness.

Bifocal lenses

They have two spherical surfaces with the inner and outer outside. The specific construction provides the widest possible overview and clarity of the image of objects. In addition, the bifocal shape is thinner compared to other types. Ophthalmologists recommend wearing it with high diopters or astigmatism, when the patient needs the lightest possible design.

Progressive

If earlier people bought several types of glasses at once (some for vision, others for watching TV or reading), today scientists suggest using progressive lenses. At the top there is an area for distance vision, and at the bottom for viewing nearby objects. They do not blur the contours of objects when moving from one type of vision to another. The only disadvantage is that it takes a long time to get used to. They are not recommended for patients with cataracts, strabismus, a big difference in diopters for the right and left eyes.

Types of glasses lenses

If previously only glass was used to correct vision, now there is wide choose other materials that are safe for humans, and the technology for making glasses is improving every time. Glass or mineral elements still remain popular due to their low cost, but they are being replaced by polymer elements that are lighter but have a higher price.

Glass (mineral)

The most popular type of lenses. They are made from special grades of mineral glass, which are characterized by high oxygen permeability. The main advantages of mineral glasses:

• Durability. The glasses can be used for a long time, while the surface remains unclouded.
• High optical characteristics and increased resistance to scratches on the surface.
• The best option for people with a high minus. Their refractive index is higher than that of plastic options.
• High throughput, thanks to which glass elements are used to create anti-glare, polarized and sunglasses.

Many advantages do not hide the significant disadvantages of glass lenses:

• They have low shockproof properties, so they are not recommended for wearing by children and athletes. To preserve the integrity of the glasses, it is recommended to store and transport such glasses in a special durable case.
• They can cause discomfort when worn for a long time, leaving marks from the frame on the bridge of the nose, causing headaches and dizziness.
• Lenses with photochromic coating have low light transmittance characteristics.

Polymer

Modern safe plastic has become an excellent alternative to glass for vision correction and quickly gained popularity among consumers. The main advantages of polymer elements:

• Short term adaptation. Compared to glass ones, they are much lighter, so they do not cause fatigue or discomfort when worn for a long time.
• Safety, low level injuries. The plastic is unbreakable, so even with a strong impact you don’t have to worry about a splinter getting into your eye.
• Plastic is easy to process, allowing manufacturers to create different designs.
• Polymer elements retain optical properties even when extreme conditions, do not fog up, help you see clearly in the rain.

When choosing polymers, it is worth knowing that depending on the color palette, the perception of the surrounding world and even your mood may be slightly distorted. For these reasons, ophthalmologists recommend choosing clear or discreet glasses that minimize color distortion. Other disadvantages of polymers include:

• They scratch, so they should only be carried in a case.
• Not suitable for people with high handicap.
• High cost of glasses lenses compared to glass elements.

Depending on which organic material was used for production, polymers are divided into three subtypes:

• Thermosets are compounds of liquid monomer molecules, which are obtained by polymerization of ultraviolet light. The most common material is CR-39. Its properties are close to crown-type minerals, but it is 40% lighter.
• Thermoplastics are polymers produced by thermal interaction or by granule casting. The most famous thermoplastic is polycarbonate. It is highly resistant to injury.
• Quasi-thermosets are a combination of several types of plastic. They have high optical properties, are resistant to damage, and do not distort space.

Types of coating

When choosing glasses, you should pay special attention to the presence of special protective coatings. It can be anti-grease, with a mirror coating, antistatic or with a dirt-repellent effect. Popular types of spraying:

• reflective - prevents damage to the eyes from bright flashes of headlights, preferably for motorists;
• hydrophobic – will protect the surface from water accumulation;
• brightening – will reduce eye strain, preferable for those who sit in front of a computer monitor for a long time;
• mirror – provides maximum protection from UV rays, used to create sunglasses.

Water repellent

It is important for every consumer that the optical surfaces of glasses remain clean and transmit maximum light even in extreme weather conditions. To meet such needs, manufacturers apply a special hydrophobic coating. A thin silicone film completely covers all irregularities, allowing water droplets to easily roll off the surface. Such glasses are easier to get rid of dirt and dust; they almost never fog up when moving from a warm room to a cold one.

Anti-glare

This spray helps protect your eyes and help you recover faster from being blinded by bright lights in poor visibility conditions. Anti-reflective coatings are used to create glasses for motorists and are very popular. The special layer relieves tension from the eyes, soothes, and refracts light well in the dark. Anti-reflective coatings are used not only to create prescription glasses, but also for accessories not intended for vision correction.

Strengthening

This coating helps maintain the integrity of the surface upon impact and prevents scratches that distort vision. Hardening coating is present only on lenses made of organic polymers; it is rarely used on glass. For different materials, manufacturers select hardening varnishes with the appropriate light refractive index.

Enlightening

A coating that is used to increase the clarity of a lens and reduce the reflection of light from its surface. The disadvantage of anti-reflective film is that it reduces impact resistance. If the glass is subjected to heavy loads, falls or impacts, the anti-reflective elements may crack or peel. For these reasons, wearing glasses with this coating is recommended only when working at a computer.

Anti-reflex

A coating that helps eliminate glare from the surface of glass. In addition, their presence interferes with eye contact between interlocutors. To eliminate the defect, manufacturers often apply an anti-reflex film to the surface of glass or plastic. It improves picture quality, the passage of light and oxygen, eliminates glare, and does not interfere with the view. In addition, the anti-reflex coating improves visual acuity.

A coating that has high level filtering ultraviolet rays. Mirror coating is used for the production of sun protection accessories, both with and without diopters. This type of coating is applied to obtain a cosmetic effect and protect the eyes; it does not have any effect on the sharpness, quality and correction of vision. Mirror coating in different colors gives the accessories a stylish look and unusual design.

Manufacturer

When choosing the right optics, you need to pay attention to the reputation of the manufacturer. Reliable and high-quality products will help preserve your vision for a long time and will last a long time. The following global brands can boast of the latest developments in the field of optics:

• Essilor (France);
• Hoya (Japan);
• Carl Zeiss (Germany);
• Rodenstock (Germany);
• Seiko (Japan);
• Nikon (Japan).

Which glasses lenses are best to choose?

There is a lot of different glass and high-quality organics that help protect vision, complement the image and even create a special attractive accent in appearance, have a neat appearance and are suitable for people with varying degrees of vision distortion. Before purchasing a particular model, you should consult an ophthalmologist. The top 10 popular models include:

We don't know which frame you will choose, or even bring your own * . For this reason, we are now giving the price only for lenses and processing and installation work.

• 2 mineral lenses from 0.00 to +/- 10.00 = from 1,200 to 2,200 rubles
• 2 polymer lenses with without coverage from 0.00 to - 6.00 = 3,000 rub.
• 2 polymer lenses with anti-reflective coating from 0.00 to - 6.00 = 3,800 rub.
• 2 polymer lenses with anti-reflective coating from - 6.50 to - 8.00 = 4,000 rub.
• 2 polymer lenses with anti-reflective coating from - 8.50 to - 10.00 = 4,400 rub.
• 2 polymer lenses with anti-reflective coating from 0.00 to - 6.00, cyl 0.50 to - 4.00 = 5,000 rub.
• The work of a master turning and inserting into a frame costs from 300 to 500 rubles. It depends on the complexity of the frame and lens mounting.

  * If you want us to insert photochromic lenses into your frame, we don't mind. There is only one condition - the frame must withstand the new lenses. Those. be no older than 5 years, without damage.

Attention: We we don't give a guarantee for glasses made from your (customer’s) frames. We don't know their quality. And even a completely new-looking frame, from a “famous brand”, purchased at a reputable optician, in 5% of cases can fall apart in the hands of a specialist. This happens for various reasons, ranging from hidden defects to fakes.