In what year were contact lenses invented? History of lens creation

Contact lenses, like glasses or LASIK, can correct almost any degree of nearsightedness, farsightedness and astigmatism. It's a great way to correct vision, 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 an irreversible effect and a number of possible complications.

The use of contact lenses gives their users some advantages over the use of spectacle correction only, 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 a 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.

The first reports of the practical use of 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 for the correction of visual impairments, but also for therapeutic purposes in 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 for a 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. They are made from jelly-like hydrogel and silicone hydrogel polymers with a high water content in the lens.
• Rigid 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 throughout the world because they have high oxygen permeability 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 for the maximum allowable time - up to 30 days without removing them.

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 dirt 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 to correct 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

Color contact 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 bandage to protect the cornea, as well as a reservoir to prolong the action of drugs, thereby promoting healing. various diseases cornea.

Which lenses are right for you?

First, the main purpose of contact lenses is to provide you with good vision by correcting your nearsightedness, farsightedness, astigmatism, or some combination of these problems.

Lenses with the same parameters, but from 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, according to which you can purchase them.

You may also need additional medications to help you adapt to your new lenses or reduce discomfort during long-term wear, such as wetting 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 that cleans, disinfects, and stores. Caring for 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, which may be asymptomatic in the initial stages.

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 periodically visit an ophthalmologist 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 large cities. Trial and error often reigns supreme in finding the perfect lens for you.

If you experience discomfort or poor vision while 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 dates 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.

The history of contact lenses begins in 1508, when the famous Leonardo da Vinci drew a diagram of an optical device in which a person with poor eyesight could see better through a ball filled with water. Almost 150 years later, the French mathematician and philosopher Rene Descartes proposed using a tube of water with a magnifying glass at the end as a lens.

The first true contact lenses, which held themselves on the eye, appeared in 1888. Swiss ophthalmologist Adolf Fick invented a lens that was made of glass and covered the entire surface of the eye, and in 1938, Hungarian ophthalmologist István Györffy was the first in Europe to make lenses from plastic. In the late 40s of the 20th century, Kevin Tauki proposed lenses that were significantly smaller in size than their predecessors. However, the hard plastic from which the lenses were made still irritated the eyes and created discomfort for the user.

In the middle of the 20th century, scientist Otto Wichterle and engineer Dragoslav Lim synthesized new material and found that it has a unique ability to absorb water (up to 38% of its own weight) and, after being saturated with water, becomes very soft and elastic. It was from this polymer that the first soft contact lens was made exactly 50 years ago. It is curious that to make it, scientists used a device consisting of a children's construction set and a bicycle - this miracle machine is still kept in the Czech museum.

Improving soft contact lenses, in the 70s of the last century in the USA, scientists developed hydrogel materials, and in 1999, breathable silicone hydrogel contact lenses appeared. Due to their high elasticity and oxygen permeability, such lenses are very comfortable. Modern contact lenses are a very thin, soft and transparent film that is placed on the surface of the eye. They are produced using innovative technologies, which allow the eyes to breathe and the lenses to remain moisturized and comfortable for the eyes. Today, people not only with myopia and farsightedness, but also with astigmatism and presbyopia can find lenses that suit them. In addition, colored contact lenses are also produced for those who want to temporarily change their eye color or hide any defect.

An important event in history was the production of the first frequent replacement contact lenses by Johnson & Johnson in 1988, which means replacing one pair of contact lenses with a new one after a short period of time. Today, all ophthalmologists are guided by the principle “the shorter the time it takes to replace one pair of lenses, the better.” This is why the first daily disposable contact lenses were introduced in the 1990s. When wearing such lenses, a new pair is put on your eyes in the morning, and in the evening you simply take them off and throw them away. This method of wearing is not only safe and hygienic, but also very convenient, because such lenses do not require any maintenance, purchase of solutions and containers for their storage.

Interest in contact lenses is growing every day, thanks to the fact that people have been able to appreciate the comfort, simplicity and convenience of their use. Today, contact lenses can be found in almost every optical shop. There, an experienced ophthalmologist will select lenses according to individual parameters and teach how to easily handle them.

A great artist, an inventor ahead of his time, a man who kept and took with him hundreds of secrets... Yes, it was he, Leonardo da Vinci, who stood at the origins of such an invention as contact lenses. Of course, more than 500 years ago these were not lenses at all, but their oldest prototype - an optical device. In 1508, in his work “The Code of the Eye,” Leonardo described the principles of light refraction and the structure of an optical device that could correct the angle of refraction of solar rays. The device itself was very simple - it was based on a ball filled with water. Looking through the ball, the person saw larger objects. We have all observed more than once how objects under water seem larger to us.

150 years later, in 1637, the French scientist and philosopher Rene Descartes improved this invention and actually made it into a device. It consisted of a tube with a magnifying glass at the end, and the tube itself was filled with water. Of course, this device was also far from perfect. The person using it could not blink. Thomas Young made several adjustments - he reduced the length of the tube, due to which the refraction also changed.

1888 Swiss physiologist Adolphe Gaston Eugene Fick proposes the first invention that could truly be called a lens. The lens was made of brown glass and was placed over the entire surface of the eye. An undeniable breakthrough was that the lens was independently held on the eye, and it could be worn for about 4 hours. Adolf Fick himself called the optical device contact glasses. In his 1896 textbook, he described as many as 8 directions of development of this industry.

But August Müller introduced this invention into medical practice and began prescribing it to patients with myopia. It happened, one might say, by accident. One of his patients did not have an eyelid. And to protect his eye from dust, Muller suggested that he wear a lens. Over time, the patient began to lose his vision and discovered that through the lens he could see much better. Then the doctor began to use the lens to correct myopia. August Müller authored a dissertation on the topic “Glasses and corneal lenses.”

A significant drawback of the lenses was this: the eyes in them became very dry, and this created discomfort. Various scientists struggled with this, trying glucose solution and cocaine drops. But only the decision of the ophthalmologist Dor, who in 1892 suggested dripping saline solution into the eyes, was successful. Saline solution was used until the end of the 40s.

Glass lenses entered medical practice. This continued until 1938. It was this year that lenses made of plastic rather than organic glass first appeared in Europe. This innovation was started by the Hungarian doctor Istvan Gyorfi. 9 years earlier, in 1929, Joseph Dallas made a lens that follows the shape of the surface of the eye. But she was also tough and didn't have much demand.

10 years after Györffy's invention in 1948, Kevin Tauki received a patent for the manufacture of corneal contact lenses. Such lenses are significantly smaller than their predecessors and have the shape of modern lenses. But even thanks to the new shape, the lenses did not become comfortable to wear. Their material is hard plastic, it was too hard and caused discomfort.

A device consisting of a bicycle and a children's construction set is still kept in the Czech museum today. The first soft contact lenses were made using this seemingly funny machine. In 1959, Czech scientist Otto Wichterle, together with engineer Dragoslav Lim, managed to synthesize a polymer that was completely new in its properties. The uniqueness of the material is that it is able to absorb water and retain it in itself, while increasing its mass almost twice – by 38%. After being saturated with water, the polymer became soft and elastic. A soft contact lens was first made from this very polymer using the same device stored in the museum.

Otto Wichterle sells his patent for the manufacture of soft contact lenses to the American company Bausch and Lomb. The Americans are improving materials and producing hydrogel lenses.

Since then, innovations in the contact lens market have occurred quite frequently.

1978 The first toric lenses were developed to correct astigmatism.

1. Rigid gas-permeable lenses were invented.

1984 CibaVision produces the first colored contact lenses. Moreover, they were given color not for cosmetic purposes, but for ease of use.

1988 Johnson & Johnson is introducing elective replacement lenses to the market.

And in 1999, daily contact lenses appeared. Today, ophthalmologists consider daily disposable lenses to be the best. It is safe and hygienic, and also does not bring unnecessary hassle with caring for lenses and changing the solution.

In the same year, silicone hydrogel lenses appeared on sale. This material is capable of transmitting oxygen to the cornea.

Today, 2% of the world's population wears contact lenses, and most of them are young women. The popularity of lenses is growing, because contact lenses are convenient and economical. Colored contact lenses today are in even greater demand than clear ones. The number of fans of nighttime contact lenses is increasing. Night lenses are a completely new technology for vision correction, unlike previous methods.

Silicone hydrogel contact lenses are considered the best on the market, and daily ones are the safest. However, if you have the opportunity to take care of them, long-term wear lenses are quite a good option. In general, lenses are very different, from different materials and to solve various problems. Therefore, the ophthalmologist selects lenses individually in each specific case.

(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%, while 70% are 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. The first lens was made and introduced into medical practice by the German inventor August Muller.

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 oxygen necessary for its normal functioning to reach the cornea.

• 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).

Long-term wear lenses 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 the water content in lens material they are divided into:

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

For hydrogel contact lenses, the higher the water content, the more oxygen they allow to reach 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. Therefore, the maximum 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 lenses to be left on the eyes overnight, much large values. 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 harm 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 should undergo preventive examinations by 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.

Precautionary measures

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 the twilight and dark, since the human pupil dilates in insufficient lighting, and the colored part of the lens comes into view, 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. Using computer control programs, lenses of complex geometry with two or more radii of curvature are produced. After turning, the lenses are polished, hydrated (saturated with water) to the required parameters and undergo 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- the oldest method of producing 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, causing it to harden. 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.

Notes

Links

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Lenses made of glass or plastic; are applied to the eyeball to correct various visual impairments, e.g. astigmatism... Big Encyclopedic Dictionary

In school physics lessons we remember that light rays travel in a straight line. Any object in their path partially absorbs light and partially reflects it at the same angle at which it falls. The only exception is when light passes through a transparent object. At the boundary of two transparent media of different densities (for example, air and water or glass), light rays are refracted to a greater or lesser extent, and amazing optical effects arise, depending on the physical characteristics of the object through which the light passes.

This property of light allows you to control the course of rays, changing their direction or turning a diverging beam of rays into a converging one, and vice versa. In practice, this can be achieved using specially processed devices made of optically transparent homogeneous material, which are called lenses (lat. lens “lentils”). Looking at an object through lenses with different physical and chemical characteristics, we will see it upright or inverted, enlarged or reduced, clear or distorted.

The simplest lens is a carefully ground and polished piece of a highly transparent substance (glass, plastic, mineral), limited by two refractive surfaces, two spherical or flat and spherical (although there are lenses with more complex aspherical surfaces). Lenses whose middle is thicker than the edges are called converging (positive), diverging (negative) are called lenses whose edges are thicker than the middle. A positive lens has the ability to collect rays incident on it at one point located on the other side of it, at focus. A negative lens, on the contrary, deflects rays passing through it towards the edges.

The simplest rock crystal lens.

Although the scope of use of lenses in science and technology is very large, their main functions boil down to a few basic ones. This is the accumulation of thermal energy of light rays, visual approximation and magnification of small or distant objects, as well as vision correction because the lens of the eye by its nature is a lens with variable curvature of surfaces. People began to use some properties of lenses earlier, others later, nevertheless, these optical devices have been known to them since ancient times.

There are different opinions about when people learned to create fire using sunlight and polished pieces of transparent stone or glass with a convex surface. We can say for sure that this method was known in Ancient Greece in the middle of the 1st millennium BC. e., since it is described in Aristophanes’ play “The Clouds”. However, lenses made of rock crystal, quartz, precious and semi-precious stones found during excavations are much older. One of the most ancient lenses, the so-called god with glasses, was discovered during excavations of Uruk, an ancient city-state in Mesopotamia. The age of this lens is about 6 thousand years, but its purpose remains a mystery.

In Egypt during the IV-XIII dynasties (III-II millennium BC), crystal lenses were used for... models of eyes in statues. Optometric studies have shown that the models are very close to real form and optical qualities of the eye, and sometimes even show visual impairments such as astigmatism.

Alabaster “idols with eyes.” Tel Brak site, Syria. IV millennium BC e.

Unfortunately, over time, the secret of making such lenses was lost; the false eyes of statues began to be made of stone or faience. The “glass eyes” technique, although with less perfection, was also used by the ancient Greeks. For example, bronze statues of the 5th century were equipped with lenses. BC e., discovered in the sea off the coast of Calabria. But there were still many centuries left before the “official” discovery of the optical properties of the eye!

During excavations in Mesopotamia, Greece and Etruria, a considerable number of crystal lenses dating back to approximately the end of the 1st millennium BC were discovered. e. A study of their decoration showed that the lenses were used both for visual magnification and as decoration. Essentially, these were true magnifying glasses with a short focal length that increased the angle of view. In addition, miniature gems were found in Greece, connected by a frame with convex lenses; these gems would not be possible to produce without optical magnification of the working field. All this indicates that magnifying glasses began to be used long before the magnifying effect of lenses was recorded in scientific sources.

When exactly lenses began to be used for vision correction has not yet been established. There is an opinion, however, not supported by anything, that lenses discovered during excavations of ancient Troy were used precisely for this purpose. In the works of the Roman historian of the 1st century. Pliny the Elder mentions that Emperor Nero, who suffered from myopia, watched gladiatorial fights through a concave lens carved from emerald, this was a kind of prototype of glasses. Some historians, based on ancient engravings, believe that glasses were invented in China in the 7th-9th centuries, but whether they were optical or sunglasses is unknown.

An Arab scientist of the 9th century was the first to seriously study the eye as an optical system. Abu Ali al-Hasan, known in Europe as Al-Khazen. In his fundamental work, The Book of Optics, he relied on the research of a Roman physician of the 2nd century. Galena. Al-Hasan described in detail how an image of an object is created on the retina of the eye using the lens. However, the essence of myopia, farsightedness and other vision defects, in which the focus of the lens shifts relative to the retina, was finally clarified only in the 19th century, and before that, glasses were selected virtually at random until the desired effect was achieved.

Mysterious optics

On the Swedish island of Gotland, in a treasure buried about a thousand years ago by the Vikings, lenses of complex aspherical shape made of rock crystal were found. This form of lenses was theoretically calculated only in the 17th century. Rene Descartes. In his work, he indicated that these lenses would give an excellent image, but for a long time not a single optician could produce them. It remains a mystery who could have polished the lenses from the Viking treasure and for what purpose.

Seller of glasses. Engraving after a painting by Giovanni Stradano. XVI century

It is believed that glasses were invented in Italy at the end of the 13th century, their invention is attributed to the monk Alessandro Spina or another monk Salvino D'Armata. The first documentary evidence of the existence of glasses dates back to 1289, and their first image was discovered in the church of Treviso on fresco painted in 1352 by the monk Tommaso da Modena. Until the 16th century, glasses were used only for farsightedness, then glasses with concave lenses appeared for the nearsighted. Over time, the shape of the glasses changed, and the frame and arms appeared. In the 19th century, Benjamin Franklin invented bifocals lenses, which in the upper part are intended for distance work, and in the lower part for close-up work.

J.B. Chardin. Self-portrait with glasses. 1775

Jan van Eyck. Madonna and Child with Canon Joris van der Paele. Fragment. 1436

Photochromic lenses (“chameleons”) were created in 1964 by Corning specialists. These were glass lenses, the photochromic properties of which were given by salts of silver and copper. Polymer lenses with photochromic properties appeared in the early 1980s, but due to significant disadvantages, low darkening and lightening rates, as well as extraneous color shades, were not widely used. In 1990, Transition optical released more advanced plastic photochromic lenses, which gained enormous popularity.

Contact lenses are considered a relatively young invention, but Leonardo da Vinci worked on their device. Many scientists thought about how to put a lens directly on the eyeball, but only in 1888 did the Swiss ophthalmologist Adolf Fick describe the structure of a contact lens and begin experiments. Mass production of contact lenses was started in Germany by the famous optical company Carl Zeiss. The first samples were completely glass, quite large and heavy. In 1937, lenses made of polymethyl methacrylate appeared. In 1960, Czechoslovak scientists Otto Wichterle and Dragoslav Lim synthesized a new polymer material, HEMA, developed a method of rotational polymerization, and produced soft contact lenses. At the same time, hydrogel lenses were developed in the USA.

As for the magnifying power of single lenses, it soon became clear that it was limited, since increasing the convexity of the lens led to image distortion. But if you place two lenses in succession between the eye and the object (eyepiece and objective), the magnification will become much greater. Using the lens at the focal point, an actual image of the observed object is created, which is then magnified by the eyepiece, which acts as a magnifying glass. The invention of the microscope (from the Greek mikros “small” and skopeo “I look”) is associated with the names of the Dutch John Lippershey and the father and son Jansen (late 16th century). In 1624, Galileo Galilei created his compound microscope. The first microscopes provided magnification up to 500 times, while modern optical microscopes can achieve 2000 times magnification.

Simultaneously with the first microscopes, telescopes (or spyglasses) appeared (their invention is attributed to the Dutch Zacharias Jansen and Jacob Metius, although the first attempts to look at stars using lenses were made by Leonardo da Vinci). The first person to point a telescope into the sky, turning it into a telescope (from the Greek tele, “far”), was Galileo. The principle of operation of an optical telescope is the same as that of a microscope, the only difference is that the lens of the microscope gives an image of a nearby small body, and a telescope of a distant large body. However, since the end of the 17th century, telescopes have used a concave mirror as a lens.

Otto Wichterle in the laboratory.

Among other things, lenses are used in the field of photography, film, television and video, as well as for the projection of finished images. The lens of a camera and similar equipment is an optical system of several lenses, sometimes in combination with mirrors, which is designed to project an image onto a flat surface. The curvature of the objective lenses is calculated so that possible aberrations (distortions) are mutually compensated. Joseph Niepce, who created one of the first cameras in 1816, borrowed a lens for it from a microscope.

Since the second half of the last century, for observations of various micro- and macro-objects along with optical systems electronics with higher resolution are used. However, lenses are still used so widely that it would be quite difficult to list all their applications.

Camera by Joseph Niepce.

Refracting telescope at Lick Observatory. California, USA.