Unexpected facts about contact lenses that will surprise you

According to statistics, in the modern world problemsvision is experienced by about 2.2 billion people. So that poor eyesight does not interfere with life, many people wear glasses - for some men and women this is already an integral part of the appearance. However, it is much more convenient to wear contact lenses: they do not get dirty during the day, do not fog up in winter and do not interfere during sports. Every day, millions of people wear lenses in front of their eyes, and they don’t even think about how they were invented, which ones are best and whether they can cause health problems. In this article, we offer you to learn some unexpected facts about lenses - be sure that something new will be revealed to you.

Statistics say that 40% of those who wear contact lenses are young people from 12 to 25 years old.

Content

• 1 First contact lenses were glass
• 2 Modern contact lenses appeared in the 20th century
• 3 Contact lenses cannot be washed with water
• 4 Lenses can cause blindness
• 5 Daily contact lenses are better than traditional ones
• 6 Prices for contact lenses depend on many factors
• 7 Lenses for astigmatism are long and expensive to manufacture.

First contact lenses were glass

Contact lenses gained popularity only after2000s. However, this is far from a modern invention - it is believed that the prototype of the lenses was invented by Leonardo da Vinci in 1508. The first lenses were a glass ball filled with water. By bringing the ball to the eye, a person with poor eyesight could better see the text and the surrounding objects.

Schematic representation of a contact lens prototype

Contact lenses in a more modern formappeared in 1888 and were also made of glass. Then the German ophthalmologist Adolf Fick created a glass lens that was put on the eye and covered the entire eyeball. It helped improve vision, but caused irritation and blocked the eyes from accessing oxygen. Because Adolf Fick's contact lenses were impossible to wear for more than two hours.

Glass lenses were also dangerous because they could break in the eye.

See also: Who discovered gravity - Isaac Newton or Leonardo da Vinci?

Modern contact lenses appeared in the 20th century

Until the 20th century, contact lenses could affordonly rich people - they were made strictly to order and made of glass. The production of lenses for the mass consumer did not begin until 1913. They were manufactured at the factories of the Zeiss company, founded by the German engineer Carl Zeiss.

Carl Zeiss - the man who launched the mass production of contact lenses

At first, lenses were made in the old fashioned way, fromglass. But then more modern materials like plastic and polymers began to be used in production. Today, many lenses are made from hydrogel, which contain large amounts of moisture. There are also silicone hydrogel lenses that provide oxygen access - they can be worn longer.

Contact lenses from the first half of the 20th century

Contact lenses cannot be washed with water

Contact lenses should only be stored inspecial solution. Typically, it consists of distilled water, disinfectants, and preservatives to increase shelf life. The purpose of the lens solution is to remove deposits accumulated during wearing and maintain elasticity.

Lens solution is needed for cleaning of contaminants and needs to be replaced regularly

Бывает так, что человек находится не дома, но lenses must be removed. In such cases, you just want to put them in a container of water. You can’t do this, because water contains a huge amount of impurities like salt and chlorine, which harm the soft polymer and deform it. Pathogenic bacteria can also live in the water.

See also: How vision deteriorates and can it be restored

Contact lenses can cause blindness

If you wear lenses without removing and do not care forthem, you can suffer from an eye infection. Their symptoms include pain in the area of ​​​​the organs of vision, redness, the presence of secretions, increased photophobia and other unpleasant phenomena.

Some amoebas can literally eat a person's eyes.

In especially severe cases, a person goes blind.In 2014, the Daily Mail reported how a 23-year-old Taiwanese woman became blind after wearing contact lenses for 1.5 years. Due to the fact that she did not take them off, Acanthamoeba amoebas accumulated in the inside of her eyes. They caused Acanthamoeba keratitis, a rare disease in which microbes literally eat the eyes. Unfortunately, the girl is blind.

Daily contact lenses are better than traditional ones

When it comes to buying contact lenses,the question arises: buy daily or traditional lenses. The first type needs to be changed every day, and the second one can be worn for several weeks or even months - it all depends on the manufacturer. It is logical that daily contact lenses are safer and more convenient, because after use they just need to be thrown away. And there is no fuss with washing and storage. The only disadvantage of daily contact lenses is their high cost.

Disposable lenses are good because they do not need to be cleaned - you can just throw them away

Prices for contact lenses depend on many factors.

Some contact lenses cost relativelyinexpensive, while others hit hard on the wallet. The price of lenses primarily depends on the manufacturer - products from market leaders such as Johnson & Johnson or Bausch & Lomb will always cost more than lesser-known companies.

Also, the cost of lenses is strongly affected by the periodwear - daily ones are more expensive than those that can be worn for a month. The material of manufacture also affects the price: hydrogel and silicone hydrogel lenses are relatively cheap, while water-gradient lenses are expensive due to high humidity and air permeability.

Good lenses do not dry the eyes and allow them to "breathe"

Finally, the price depends on the complexity of manufacturing.Ordinary lenses can often be bought at any optical store, but lenses for astigmatism and other complex options are usually made to order and are more expensive.

See also: Millions of people experience "visual snow" in their eyes. What is it and how dangerous is it?

Lenses for astigmatism are long and expensive to manufacture.

Some people suffer from astigmatismIn this disease, the human lens or cornea has an irregular shape. In healthy people, the light focuses exactly on the retina, while in people with astigmatism, the light falls unevenly. As a result, the eyes do not see everything clearly, as in a crooked mirror.

Lenses for astigmatism are needed in order for the lightagain began to fall exactly on the retina. Ordinary lenses are bowl-shaped with smooth edges. The structure of lenses for astigmatism combines the shapes of a cylinder and a sphere - they are flat in the center, and return to a spherical shape at the edges.

Normal vision (left) and vision with astigmatism (right)

Lenses for astigmatism have another feature- they always occupy a certain position on the eye and do not change it. In order for the lenses to always fit correctly, the technology of their stabilization with the help of the eyelids was created.

Did you like the article? Then share it with your friends and subscribe to our Zen channel. We are already more than 100 thousand people!

In today's world, you can see perfectlywith glasses and contact lenses. But they require regular care and money, so some people decide to have vision correction surgery. If you have thought about this, we have a comprehensive article about modern methods of vision correction - read and you will understand which one is better.