Today, contact lenses are extremely popular. They have successfully replaced glasses and effectively correct myopia and farsightedness, astigmatism and presbyopia. They are also used for decorative purposes - to change or emphasize eye color. When and by whom were lenses invented?

At all times there have been people with poor eyesight. Of course, in recent years this problem is becoming global in connection with the development information technology. Computer, tablet or e-book Today it is difficult to surprise anyone. It is not surprising that from lasting influence on the eyes visual functions modern people begin to deteriorate, requiring constant use of glasses or. However, with similar problems people encountered this in ancient centuries, but the reason for the decline in visual acuity was not computers and televisions. When did the first lenses appear?

Prerequisites for creating lenses

It's hard to believe that the very first mention of contact lenses ah belongs famous artist Leonardo da Vinci. It dates back to 1508 and is found in the book “The Code of the Eye”. It was da Vinci who created the drawing of future lenses. The image was a glass sphere filled with water, thanks to which a person with poor eyesight could better see surrounding objects. However, it is impossible to say that Leonardo da Vinci was the creator of the very first model of contact lenses. Rather, he paid attention to the existing refractions of light that enters the eyes. It was the mention of the artist that served as an incentive for his followers to invent lenses. One of them was the French philosopher, mathematician and physicist Rene Descartes. In 1632, he first put a glass container filled with water over his eyes, because this is how da Vinci described future contact lenses. However, it was impossible to wear such an invention. Firstly, it was completely inconvenient to use and significantly constrained the movements of its owner. Secondly, correcting vision with their help was quite difficult, since a container filled with water quickly fogged up, thereby further worsening visual functions. Thirdly, the use of such lenses prevented a person from blinking, thus disrupting natural physiological processes and promoting drying of the cornea.

The right contact lenses

After another two hundred years, the British physicist and astronomer John Herschel returned to the topic of creating contact lenses. It was he who described in detail in his writings what a real and, most importantly, correct contact lens should look like. Herschel called its most important characteristic the ability to repeat the shape of the eye. Today, each of us understands that this particular feature is the main one for lenses, but in those days, it was quite difficult for scientists to understand exactly what contact lens models that could not only correct visual impairments, but also remain comfortable to wear should actually look like for any user.

The first glass lenses

Who developed the very first glass lens? This person was the German glassblower Friedrich Müller, and this memorable event in the field of ophthalmology took place in 1888. Müller did not set out to create a contact lens. He just wanted to help his close friend see the world around us in bright colors. It so happened that a friend lost an eyelid. Why this happened is unknown, but the fact remains. Moreover, Müller did not seek to develop optical products that could correct vision. The friend, who was left without an eyelid, repeatedly complained to Friedrich that the mucous membrane of the eye quickly dried out, causing his vision to become blurred. In those days, no one used contact lenses yet, and therefore this method of correction remained unexplored until the end. Muller positioned his invention as protecting the eye from the negative effects of environment. Having thus developed the first lenses, the glassblower devoted himself to further creating similar models, but this time intended for a wide range of clients. The lenses he created completely followed the shape of the eye and were two-color. The white part was adjacent directly to ocular sclera, and transparent - to the iris and pupil.

When did lenses appear on the optical market?

The very first lenses to go into mass production were created by the famous German brand Carl Zeiss. Although calling him famous would not be entirely true. At that time, the company had just appeared on the market and was actively engaged in the production of microscopes. The founder of the company, Karl Zeiss, considered it his duty to continue the work begun by his fellow countryman, the German glassblower Friedrich Müller. Zeiss managed to give the contact lens the required form so that it can repeat the shape human eye. The difficulty was that the lenses he produced were of the same size, because they were all manufactured by specialists from his company using the same equipment. However, the problem with identically manufactured lenses was soon solved. This was facilitated by Carl Zeiss’ acquaintance with Otto Schott, a German chemist specializing in the production of glass products. Together they managed to create lenses that, although slightly different from each other in size, allowed many people to correct their vision with contact lenses.

Carl Zeiss and Otto Schott

Plastic lenses

The next stage in the history of optical products was the unique discovery of the Hungarian doctor Istvan Gyorfi. He managed to develop a lens made of plastic. It is not at all surprising that most people were quite uncomfortable with glass lenses. Many of them complained of discomfort and pain in the eyes when using them, and children were completely prohibited from wearing them. However, the lens, made of plastic, was also not ideal. The material used in its creation was called Plexiglas and was characterized by increased rigidity, which also caused inconvenience during operation, albeit not for such a large number of people. Despite this, Györffy received a patent for the production of contact lenses developed on the basis of Plexiglas.

Who invented soft lenses?

When did soft lenses appear and who is their creator? The first soft material was used by the Czech scientist Otto Wichterle. For several years he worked in research institute one of the country's shoe companies, being the head of the department for processing polyamide and plastics. Few people know that lenses were preceded by the creation of silicone, the material from which soft models began to be created. Wichterle managed to develop this polymer as follows. Interested organic chemistry, Otto developed a method for winding polyamide thread onto a spool. It was called silicone. Then he became interested in the synthesis of polymer materials. He tried to understand which material was best suited for the production of contact lenses. So he managed to develop a hydrogel that could absorb about 40% of water. It was completely transparent and had all the necessary properties. In the mid-50s of the last century, the material was patented, after which Otto Wichterle received a patent for further production of lenses.

Colored lenses are made from the same materials as traditional corrective lenses. Unlike colorless optics, tint, cosmetic or carnival products are made using multilayer technology - at least three layers are used, one of which contains pigments. Otherwise, in terms of production and materials for the layers in contact with the eye and eyelid, there are no special differences from corrective optics.

Layers of colored lenses

Color optics consists of the following layers:

• External, in contact with the eyelid and exposed external influences- dust, ultraviolet radiation, etc.
• Medium, containing special pigments to give the iris a given color.
• Inner which directly sticks to eyeball and holds the lens on the eye.

The middle layer with coloring materials does not interact directly with the eyelid or eye, and therefore is completely harmless to the mucous membrane, pupil, and iris. At the same time, in the production of tints (they make the natural color of the iris more expressive and are intended only for light shades eye) uniform coloring is used over the entire surface of the lens, including the pupillary area.

In the first hours of wearing such products, “the surrounding world is painted in the color of the lens” and the color picture is distorted, but then the eye adjusts and the image becomes normal, as it was before putting it on. For cosmetic ones (dramatically changing the color of the iris), the pupil area is not colored. Usually the unpainted part is made slightly larger than the pupil, so that in low light, when the pupil dilates, the pigmented part does not interfere with visibility.

As for carnival products with non-standard prints (red, black and other iris colors, cat eye etc.), then in them it is possible to narrow the pupillary zone to achieve a special theatrical effect.

Materials used for contact optics

In the production of colored lenses, various technologies are used (mainly casting) and large number polymers - polymacon, senofilcon, omafilcon, balafilcon, vilfilcon and others. In total, according to the FDA classification, there are 4 groups depending on the polymers used and moisture content.

Lenses can be:

• Tough. Materials made from rigid polymers can be gas permeable (GPL) or gas impermeable.
• Soft. Products made from soft polymers. There are hydrogel (HG) and silicone hydrogel (Si-Hg).

Rigid polymers are increasingly used in the manufacture of contact optics. Such lenses are smaller in size compared to products made from soft polymers - there is a risk of falling out of the eye during sports activities. The disadvantages of optics made from hard polymers is that they take a relatively long time to get used to.

Soft polymers (eg HEMA) are highly hydrophobic. The products absorb moisture and transmit oxygen well to the cornea due to the evaporation of liquid.

The HEMA polymer (hydroxyethyl methacrylate) began to be gradually replaced by silicone hydrogel from the late 90s to early 2000s. This material allows oxygen to pass through better, retains its properties throughout the entire period of wearing and does not require much getting used to.

Safe, chemically inactive pigments that do not react with polymers are used as dyes for the middle layer.

Are colored products harmful to the eyes?

Since all contact layers are made from the same eye-safe materials as corrective optics, there are no health risks. The layer with pigments is completely isolated from the mucosa. The pupil area in tint and cosmetic products corresponds to the size of the human pupil, so there is no discomfort, reduction in viewing angle, or visibility. The main thing is to follow the manufacturer's instructions and be sure to consult with an ophthalmologist before purchasing. You can view the assortment in "Lenses for everyone"

Contact lenses, like glasses or LASIK, can correct almost any degree of nearsightedness, farsightedness and astigmatism. This great way vision correction, healthier and more convenient than ever. Today, contact lenses, if they are correctly selected, are comfortable the first time they are used.

Currently, contact vision correction in Russia is experiencing rapid development. Contact lenses are easy to use and can be an alternative to refractive surgery, which has irreversible effect and a number of possible complications.

The use of contact lenses provides their users with several advantages compared to using only spectacle correction, since the contact lens and the eye form a single optical system, thereby achieving high quality vision. This type correction is extremely convenient for athletes and other professions where wearing glasses can be not only inconvenient, but also present certain difficulties.

If there is a large difference in vision between the eyes, it is also convenient to use contact lenses, since glasses big difference is poorly tolerated and affects the overall comfort when using glasses, sometimes forcing them to abandon them altogether and resort to surgery.

Not many people know that contact correction first appeared in the 16th century. In the literary heritage of Leonardo da Vinci and Descartes, drawings of optical devices were discovered that are prototypes of modern contact lenses.

First reports about practical application contact lenses date back to 1888. And since that time, the process of improving manufacturing technology, materials and the design of lenses has already been actively underway.

The indications for the use of contact lenses have gradually expanded: soft lenses are used not only to correct visual impairments, but also to therapeutic purpose with some eye diseases. In addition, it became possible to produce cosmetic, colored, and even carnival lenses.

Currently, many types of contact lenses can be grouped according to certain characteristics and properties:

• The material from which they are made
• Wearing time without removal
• Replacement frequencies per new pair
• The design and shape of the lens itself

Contact Lens Materials

Depending on the material used, there are three types of contact lenses:

• Soft lenses are the most popular today. Manufactured from jelly-like hydrogel and silicone hydrogel polymers, with high content water in the lens.
• Hard gas permeable lenses are made from silicone-based materials and have the most high rate permeability to oxygen. They are especially good for correcting presbyopia and high degrees of astigmatism.
• Hard lenses made of PMMA (plexiglass) are obsolete and practically not used.

In the 80s, the first hydrogel-based soft contact lenses appeared. With the advent of silicone hydrogel materials, soft contact lenses have rightfully gained immense popularity all over the world because they have high permeability to oxygen and are less prone to dehydration of the lens itself.

Contact lens wearing time

In 1979, extended wear lenses were first approved, allowing patients to sleep with their lenses in place for up to 7 days in a row. Until this time, everyone was required to remove and clean their lenses daily at night.

Today, lenses are classified according to wearing time as follows:

• Daytime lenses - should be removed at night
• Long-term wear – can be worn overnight, usually for seven consecutive days without removal
• "Continuous wear" contact lenses - this term refers to some types of modern lenses that can be worn as much as possible. valid time– up to 30 days without removing.

Scheduled lens replacement time

Even with proper care, contact lenses, especially soft ones, should be replaced regularly with a new pair to prevent deposits and contaminants on their surfaces, which significantly increase the risk of eye infections and discomfort.

In accordance with the time of planned replacement, soft lenses are divided into:

• Daily lenses – must be destroyed after one day of wear
• Frequent scheduled replacement - service life one to two weeks
• Scheduled replacement - replacing lenses once a month or every few months
• Traditional – service life of soft lenses – from six months or more
• Gas permeable contact lenses are more resistant to deposits and contamination and do not have to be changed as often as soft lenses. Often, GP lenses can last a year or more before they need to be replaced.

Contact lens design

Spherical contact lenses: designed to correct nearsightedness (myopia), farsightedness (hypermetropia).

Bifocal contact lenses: have two zones - for distance and near vision, designed for correction age-related farsightedness(presbyopia).

Orthokeratology contact lenses: designed for use while sleeping. The principle of their action is to change the shape of the cornea, which allows you to do without lenses during the day.

Toric contact lenses: Used to correct astigmatism.

Additional options for contact lenses

Colored lenses. Many of the types of lenses used to correct vision abnormalities come in a variety of color options that can enhance the natural color of your eyes - for example, make green eyes even more saturated green, or completely change the color of your eyes. appearance eye.

Carnival “Crazy” lenses. They can give you an incredible appearance and expression in your eyes - the look of a cat, a zombie or a vampire, whatever your imagination suggests.

Lenses for prosthetics. Colored contact lenses can also be used for cosmetic purposes in people who have suffered severe injuries, burns or eye diseases to hide defects that are visible to others.

Therapeutic contact lenses are basically soft contact lenses that can be used as a corneal bandage and also as a reservoir to extend the wear. medicinal substances, thereby promoting healing various diseases cornea.

Which lenses are right for you?

Firstly, the main purpose of contact lenses is to obtain good vision by correcting your nearsightedness, farsightedness, astigmatism, or some combination of these problems.

Lenses with the same parameters, but different manufacturers may be tolerated differently by the patient.

Secondly, the lenses must match the individual parameters of your eyes. There are thousands of combinations of diameter, radius of curvature and other parameters that ensure comfortable wearing of lenses. Often, lenses with the same parameters, but from different manufacturers, can be tolerated differently by the patient.

Only an ophthalmologist or optometrist can professionally select contact lenses for you, taking into account the two above criteria, as well as all your wishes - color, wearing time and method of care. As a result of the examination, you will receive a prescription for contact lenses, with which you can purchase them.

You may also need additional medicines to facilitate adaptation to new lenses or reduce discomfort when long-term wearing, for example, moisturizing drops.

Contact lens care

Contact lens care - cleaning, disinfection and storage - has become much easier than before.

Daily contact lenses will completely relieve you of care worries.

Several years ago, there was a need for various detergents, disinfectants and enzyme tablets for proper care. Today, most people can use "multi-purpose" lens care solutions - meaning one product both cleans, disinfects and stores. Care soft lenses has distinctive features from caring for hard contact lenses.

Of course, you can free yourself from contact lens care entirely by choosing to wear disposable contact lenses.

Complications and discomfort

A person who decides to use contact lenses should always be well informed about possible complications, as well as navigate various types of symptoms and manifestations. It is important not to forget about follow-up examinations to exclude complications that may initial stages be asymptomatic.

In addition, a number of factors, both general and local, can influence the tolerability and level of comfort when wearing contact lenses. People react differently to different lens materials and cleaning products.

The correct "parameters" of your lenses - optical power, diameter and curvature - can be finally selected after a certain period of wear. This is especially true for more complex lenses such as bifocals or toric contact lenses for astigmatism.

It is important to visit an ophthalmologist periodically for preventive purposes.

Improper care and non-compliance with wearing contact lenses can lead to very sad consequences, including loss of vision. Unfortunately, as practice shows, such cases are not uncommon, even in major cities. Trial and error often reigns supreme in finding the perfect lens for you.

If you experience discomfort or poor eyesight When wearing contact lenses, you should consult a specialist. To learn about the problems you may encounter when wearing contact lenses, read the article “Complications and Discomfort When Wearing Contact Lenses.”

Where to buy lenses

Today, contact lenses are sold everywhere: in opticians, pharmacies, kiosks in the metro, and online stores. But you need to know that the initial selection of contact lenses, determination of their parameters, selection of replacement periods and duration of wearing is carried out only by an ophthalmologist in a specially equipped contact correction room.

In addition, during the selection of contact lenses, the patient is taught to independently put on and remove contact lenses, and the doctor also gives all the necessary recommendations.

Buying lenses without consulting a specialist is quite a risky activity in terms of complications. For details on purchasing contact lenses online, read our article on purchasing lenses online.

No matter how surprising it may sound, attempts to create contact lenses were made at the end of the 16th century. And the first experiment belongs to Leonardo da Vinci himself. The archives remaining from the great master contain sketches from 1508, which depict a device intended for vision correction. according to the sketches, optical system should be installed on the eye and correct vision. Today, scientists are confident that it was this invention of Leonardo that became the prototype of modern contact lenses.

However, the master’s invention did not find due recognition at that time and was safely forgotten for almost 400 years. It was only in 1887 that the German glassblower Friedrich Müller took advantage of Leonardo's idea. And it all turned out because one of Muller’s acquaintances did not have an eyelid, and to help the sufferer, the glass blower made a glass spherical lens and placed it on his eye. This lens protected the eye and prevented moisture loss. The patient wore this lens for 20 years, and age-related changes In his vision, he began to notice that under the lens his eye could see better. After this, Müller began making such lenses, helping people with visual impairments. These lenses were prosthetic lenses that molded to the shape of the eye. The part of the lens that is adjacent to the sclera was made of white glass, and above the pupil was made of transparent glass.

Almost 30 years have passed and the Carl Zeiss company has launched the production of special sets of contact lenses. Each set contained lenses with different parameters, this greatly facilitated the selection of lenses for the eyes of a particular person.

Until the mid-50s of the 20th century, all lenses were made of glass, and they had similar parameters, the diameter was 20-30 mm, and the thickness was 1-2 mm. These lenses covered almost the entire visible part of the eye, both the sclera and the cornea. Because of this, a large amount of fluid accumulated under them, this caused swelling of the cornea, and painful sensations at the patient. After patients removed their lenses, they had to long time be treated to restore the transparency of the cornea.

A major breakthrough was the fact that in 1947, Kevin Touhey created the first small-diameter contact lens, it covered only the cornea, and was made of plastic, and not like glass before. It was after this that the contact lens became the shape it has now.

A new word in the production of contact lenses was the invention of the Czech scientist Otto Wichterle in the late fifties. He invented a transparent, stable polymer that is excellent for the production of soft contact lenses. This polymer had the ability to retain moisture and allow the eyes to “breathe”, and it did not cause corneal edema. And since 1971, Wichterle’s invention has formed the basis for mass production contact lenses, making them accessible to everyone.

(that is, to increase visual acuity), with the exception of decorative and cosmetic contact lenses - they can not only correct vision, but also decorate the eyes.

Contact lenses, according to experts, are worn by about 125 million people in the world. The method of vision correction using contact lenses is called contact vision correction.

More than 40% of contact lens wearers are young people aged 12 to 25 years. And among those who put on contact lenses for the first time, the proportion of young people under the age of 35 is almost 90%, with 70% of them being women.

Story

The idea of ​​using contact correction was first expressed by Leonardo da Vinci in 1508. The archive of his works contains a drawing of an eye with a bath filled with water - a prototype of modern contact lenses. In 1888, Adolf Fick described the first glass lens with optical power. He made the first lens and introduced it into medical practice German inventor August Müller.

Until the 1960s, contact lenses were made only from plexiglass (PMMA). Hard PMMA lenses were uncomfortable to wear and caused a feeling foreign body in the eye and did not allow the necessary for its normal functioning oxygen.

• Material
• Radius of Curvature (BC, BCR)
• Lens Diameter (D, OAD)
• Optical power
• Cylinder axes
• Lens Center Thickness
• Wearing mode
• Replacement frequency
• Design

• 1 day (one-day contact lenses),
• 1-2 weeks,
• 1 month (monthly replacement lenses),
• 3 or 6 months,
• 1 year (traditional lenses).

Lenses long term wear without replacement (6-12 months) are packaged in bottles. Lenses that need to be replaced more frequently are packaged in blisters.

• daytime (lenses are put on in the morning and removed before bedtime),
• prolonged (lenses are worn for 7 days and not removed at night),
• flexible (lenses are worn for 1-2 days without removing),
• continuous (it is possible to wear lenses continuously for up to 30 days without removing them at night; the mode is allowed only for some silicone hydrogel lenses; its use requires consultation with an ophthalmologist).

Contact lens design:

• Spherical myopia and hypermetropia.
• Toric contact lenses are used to correct myopia and hypermetropia in the presence of astigmatism.
• Multifocal contact lenses are used to correct presbyopia.

Aspherical design can be used in all types of lenses to improve vision quality.

Various materials are used to make contact lenses. Most of them are hydrogel polymers. Silicone hydrogel There are only about 10 materials.

Contact lens material largely determines its properties. The main characteristics of the material include water content And oxygen permeability.

Depending on water content in lens material they are divided into:

• lenses with low content water (<50 %),
• lenses with average water content (about 50%),
• lenses with high water content (>50%).

For hydrogel contact lenses than more content water, the more oxygen they transmit to the cornea of ​​the eye, which has a positive effect on eye health. However, as the water content increases, hydrogel lenses become too soft and difficult to handle. That's why maximum content water content in hydrogel lenses does not exceed 70%. For silicone hydrogel lenses, oxygen transmission is not related to water content.

Contact lens ability let oxygen through characterized by a special coefficient Dk/t (Dk is the oxygen permeability of the lens material, and t is the thickness of the lens in the center). For hydrogel lenses, Dk/t is usually in the range of 20-30 units. This is enough for daytime wear. In order for the lenses to be left on the eyes overnight, much higher values ​​are required. Silicone hydrogel contact lenses have a Dk/t of the order of 70-170 units.

Radius of curvature paired with Diameter contact lens affects how the lens “fits” in the eye. Typically lenses are available in one or two radii of curvature. Poor fit of a contact lens due to a discrepancy between the radius of curvature of the lens and the shape of the cornea can lead to refusal to wear contact lenses.

Basic optical parameters contact lens: sphere power (in diopters, with a "+" or "-" sign), cylinder power (in diopters) and cylinder axis position (in degrees). The last two parameters are indicated for toric contact lenses used to correct astigmatism.

Designations for eyes in the recipe: O.D.- right eye, OS- left eye.

The parameters of contact lenses for the left and right eyes of one patient, generally speaking, may not be the same.

Hygiene and contraindications

With the correct medical selection, compliance with all recommendations for wearing time, handling and processing, contact lenses cannot cause harm to vision.

If hygiene rules are not followed or lenses are processed incorrectly, the mucous membrane of the eye may become infected. If the terms of wearing are not observed, regular replacement lenses are worn out regularly, or lenses with low oxygen permeability are used, gradual growth of blood vessels into the cornea of ​​the eye (corneal neovascularization) and other complications are possible, which are often irreversible and are a contraindication to further wearing contact lenses.

Anyone who wears contact lenses must undergo preventive examinations an ophthalmologist at least once a year.

Wearing contact lenses in frosty weather is not contraindicated.

Colored contact lenses

Manufacturers of contact lenses sometimes emphasize their cosmetic role in advertising.

Colored contact lenses are used to radically change the color of the iris, tint- respectively, to enhance or change the shade. Colored and tinted contact lenses come with both diopters, for correcting vision and changing the shade of the eyes at the same time, and “zero”, for those who want to achieve only a cosmetic effect.

Colored lenses do not affect the color of the perception of surrounding objects, since they are transparent in the center.

Precautions

If the lenses are chosen incorrectly and “float” in the eye, interference and discomfort are inevitable, you should consult a doctor. It is not recommended to wear colored and tinted lenses in twilight and dark time days, since the human pupil dilates in insufficient lighting, the colored part of the lens falls into the visibility zone, which is perceived as interference, a veil before the eyes.

It is prohibited to drive a car wearing colored or tinted contact lenses. and also perform other work that requires increased visual attention and speed of motor reactions.

Swimming and bathing in lenses is only possible if you use sealed swimming goggles or a mask. You cannot go to the sauna or bathhouse while wearing lenses. If you took a shower or swam wearing lenses (without glasses or a mask), you must immediately change them for a fresh pair.

Largest contact lens manufacturers

• Cooper Vision
• Maxima Optics
• Interojo

Production of contact lenses

There are several methods for making lenses: centrifugal molding, turning, casting, as well as methods combining these techniques.

• Turning- “dry” polymerized workpieces are processed on a lathe. By using computer programs lenses of complex geometry with two or more radii of curvature receive control. After grinding, the lenses are polished, hydrated (saturated with water) until required parameters and pass chemical cleaning. At the end of the cycle, the lens is tinted, checked, sterilized, packaged and labeled.

• Casting- a less labor-intensive method than turning. First, a metal matrix mold is made, each set of lens parameters has its own. Plastic copy molds are cast using the matrix, into which a liquid polymer is poured, which hardens under the influence of ultraviolet radiation. The finished lens is polished, hydrated, tinted, sterilized and packaged.

• Centrifugal molding- most old way production of soft contact lenses, but is still used today. The liquid polymer is injected into a mold rotating at a certain speed, where it is immediately exposed to temperature and/or ultraviolet radiation, as a result of which it hardens. The workpiece is removed from the mold, hydrated and subjected to the same processing as during turning.

One example combined method contact lens production - Reversible process III. With this method, the front surface of the lens is obtained by centrifugal molding, and the rear surface is obtained by turning.