Contact vision correction is the correction of defects with the help of lenses. The use of lenses, materials for their manufacture. Indications for contact correction

In 1962, George Essen created corrective lenses, calling them orthofocus. A few years later, Newton Wesley suggested that the science of them be called orthokeratology. Unfortunately, the first orthokeratology lenses were unpredictable and unstable, and the effect of their use was weak. They were made of airtight materials, which is why they were only allowed to be worn during the day. Since then, orthokeratology has come a long way, and today we have a large selection of high quality corrective night lenses.

How lenses work

Let's figure out how night lenses work. They squeeze the cornea, thereby correcting its shape. At the same time, only the thickness of the epithelium, the superficial thin layer of the cornea, changes in a person. The stroma and endothelium remain unchanged.

A person puts on hard lenses at night and goes to bed peacefully. While he is resting, the devices do their work. They gently press on the cornea, correcting irregularities, correcting thickness, shape and curves. After waking up, a person removes medical night lenses and goes about his business. He has good eyesight throughout the day.

Validity

Previously, doctors were sure that orthokeratological hard lenses have only a temporary effect, and after their removal, the cornea soon returns to its former shape. However, recent Scientific research proved otherwise. As it turned out, with many months of use, hard lenses can cause a lasting effect. In children who wore them for about 4 years, minor corneal changes persisted for more than two weeks.

Modern night lenses for the eyes can correct vision for a period of one to three days. The duration of their action depends on the degree of myopia and individual characteristics human eye. Immediately after removing the lenses, visual acuity rises to 100%, but in the evening it drops by 0.5-0.75 diopters.

Peculiarities

When it comes to choosing a remedy, people are lost and unable to make a decision. Therefore, we will compare night lenses for restoring vision with daytime ones. This will help you evaluate their advantages and disadvantages, as well as understand which ones to choose.

Indications and contraindications

Night contact lenses are indicated for people with myopia and myopic astigmatism. They should be chosen by men and women who do not want to do laser correction vision. Medical lenses save people whose professions do not allow the wearing of glasses or any other means of correction. They can be used by athletes, the military, workers of chemical plants and people who are forced to stay in dusty rooms for a long time.

Night lenses to improve vision are suitable for children and adolescents with progressive myopia. Scientists conducted a series of studies and concluded that contact correction slows down the development of myopia by more than two times.

Contraindications to the use of corrective night lenses:

• corneal deformities in the form of keratoconus or keratoglobus;
• severe dry eye syndrome;
• astigmatism over 1.75 and myopia over 6.5 diopters;
• , lagophthalmos;
• , blepharitis, keratitis and others inflammatory diseases eye.

Application in childhood

Orthokeratology is beneficial for children and adolescents with myopia as it helps them maintain their vision. The use of hard night contact lenses is The best way stop the rapid development of myopia. Their use helps to relieve visual fatigue and tension, temporarily restore vision and even improve it.

Night lenses can be used in children over 6 years of age. Only an experienced ophthalmologist should select them. Before prescribing a corrective agent, the specialist must carefully examine the child and make sure that he does not have accommodation spasm (the so-called false myopia). Unlike true myopia, this disease is treated with eye drops. Wearing lenses in this case is prohibited. With adequate treatment of false myopia, the baby's vision will soon improve.

Selection rules

Night lenses - which one is better? Orthokeratology rigid night lenses can be purchased from a contact lab or optometrist. Only an ophthalmologist who has completed special training courses and has all the necessary skills can pick them up. You cannot make a choice on your own.

A person who previously wore soft contact lenses should stop wearing them for 2 weeks. Only after that he can go for a consultation with a specialist.

The selection of lenses begins with an examination, which includes:

• determination of visual acuity;
• refractometry;
• keratotopography;
• keratometry;
• other necessary studies.

The choice of orthokeratology lenses is quite complicated, which is why the specialist has to reconsider several options. As a result, the doctor chooses a correction tool that is best suited in all respects. A person puts on lenses and sleeps in them for 6-7 hours, then comes back for a second examination. If they fit, the doctor allows you to use them all the time.

Paragon night lenses are the most popular in our time. They can be purchased at many opticians and even ordered online. Note that when buying them, a person receives free consultation ophthalmologist.

Side effects when using

At first, wearing orthokeratology lenses can lead to side effects. Patients often have a feeling of dryness in the eyes. You can fix the problem with special moisturizing drops.

In the early days of using lenses, a person may notice colored reflections and light circles around light sources. Their appearance is caused by an active change in the shape of the cornea. Soon, all unpleasant symptoms disappear, the patient gets used to the lenses and feels great. After 1-2 weeks, his vision rises to 100%.

Can there be complications?

Night lenses for vision correction cause complications much less often than usual. Since they are made of breathable materials, they do not interfere with the breathing of the cornea. Moreover, they are very convenient to use and do not violate the habitual way of life of a person. Unwanted Consequences appear in case misuse lenses.

Possible complications:

• under-correction or over-correction;
• swelling, inflammation, erosion of the cornea;
• allergic conjunctivitis and keratitis.

With careful care of the lenses, you can avoid any unpleasant complications. In case of itching, discomfort, watery eyes or other suspicious symptoms, you should immediately consult a doctor.

night lens care

Lenses to restore vision should be worn at night and removed in the morning. After removing them, gently wipe them with your fingertips and rinse with running water. Store lenses in a special container with. The liquid must be changed every day, and the container - at least once every 3 months. The lens remover is recommended to be used no longer than 6 months.

Rigid lenses should be used carefully and carefully. They are made of a hard but brittle material, so they can easily break if dropped or crushed. If chips, scratches, cracks or other major defects appear in the lenses, they will have to be replaced with new ones.

Orthokeratology enables people to see clearly without glasses or vision correction surgery. To do this, they just need to put on special hard lenses at night. In the morning, after removing them, vision is restored to 100% and remains so all day. Orthokeratology lenses are comfortable and safe to use, which is why they are increasingly being used for vision correction.

Useful video about night lenses

The effect of night lenses is reversible, which makes it necessary to wear orthokeratological lenses every night or every other night (this parameter is individual).

The first orthokeratological (OK) lenses, and with them the term itself, appeared in the early 60s. True, at that time it was necessary to wear lenses enough a long period, and the results of OK therapy were difficult to predict, so this method not received wide distribution. In the early 90s, with the advent of modern diagnostic equipment and the possibility of manufacturing contact lenses of complex geometry, orthokeratology received a new impetus to development.

In the early 2000s, for the first time, they started talking about night OK therapy: putting on lenses at night, the patient removes them in the morning, and the next day he sees perfectly without any corrective optics.

Correction range

According to numerous studies, it is reported that 100% correction with night OK lenses is possible in the range from -1.5 to -4 diopters (D). However, there are reports of possible correction myopia and -5 D. Moreover, some patients managed to correct myopia -6 D.

The greatest effect of correction (up to 75%) of vision, as a rule, is achieved already in the first use of such lenses. Full correction and stabilization of the results occurs by 7-10 days of using night lenses. During the day, when the lenses are not worn, there is a slight decrease in the effect, down to -0.75 diopters. Maintaining long-term vision correction requires the use of OK lenses every night or every 2 or 3 nights. Usually patients are satisfied with the mode of wearing lenses night after night.

OK lenses have no age restrictions, they are suitable for children and adolescents, which is very important, because up to 18 years surgery myopia cannot be carried out. Such lenses are also suitable for adults who, for some reason, contact correction is impossible or there are contraindications to surgery.

How it works?

With myopia, light rays, passing through the optical media of the eyes, have the property before. In order for the focus to fall on , it is necessary to "weaken" the refraction of the rays. This is achieved by changing the shape, for which it is necessary to make it flatter. By the way, it is this principle that underlies most surgical techniques vision correction. Orthokeratology also uses it: rigid lenses, by pressing down on the cornea, make it flatter, as they provoke a redistribution surface layers cells, which, in turn, refract light rays more weakly, and the image is focused on the retina. After removing night lenses, the cornea can retain its shape for some time, and the patient sees well without any correction. But gradually the cornea is leveled to its original shape, and OK lenses have to be put on again.

Benefits of ok therapy

Night OK therapy has a number of important advantages in relation to other methods of vision correction:

First and foremost, during the day the patient does not need correction at all, i.e. it is free from glasses, lenses and any restrictions that come with poor eyesight. It is worth recalling that in some cases, spectacle or contact correction is simply unacceptable due to the type of activity of the patient (pilots, swimmers, hockey players, etc.), and surgical treatment is delayed due to medical indications or personal reluctance. In such cases, the only possible option are night lenses.

In these lenses, the cornea of ​​the eye does not suffer from a chronic lack of oxygen, as when wearing contact lenses all the time, because during the day the patient is without them, and oxygen has free access to the cornea. At the same time, we will not deny that at night, in the presence of lenses and closed ones, hypoxia intensifies. But during the day, nighttime hypoxia is more than compensated by free access to the cornea of ​​air and oxygen. Also excellent eyesight.

Wearing contact lenses significantly reduces the frequency of blinking movements and impairs tear flow, which becomes the cause. OK therapy minimizes the risk of dry eye syndrome, as the lenses are daytime missing, and physiological mechanism distribution of tear fluid is preserved. Together with the tear, nutrients and bactericidal substances enter, are removed tiny particles dust, microorganisms, metabolic products.

The use of OK lenses practically does not give impetus to the development allergic manifestations, in addition, the risk of occurrence of and decreases.

With such lenses, you can use any cosmetics and not be afraid that its particles will settle on the surface of contact lenses.

No need to remove lenses when swimming, or swim with protective glasses. In OK lenses, high-speed driving by car or bicycle is possible without fear that the lenses will “dry” in the wind.

There is no need for a container for lenses, as well as the need to apply drops after talking with smoking friends in a confined space.

If in time the opportunity surgical correction becomes achievable, then you should just stop wearing OK lenses. After some time, the cornea will return to its original shape and the operation will take place.

How to choose OK lenses and possible complications

Orthokeratology lenses should only be fitted by a specialist in OK therapy. During the examination, the doctor performs certain diagnostic procedures:

(measurement of the curvature of the cornea);

(drawing up a "map" of the surface of the cornea);

Finds out all the contraindications for the use of such lenses.

Only after that, the procedure for selecting night lenses begins. Sometimes more than one pair of OK lenses is moved before the desired effect is achieved, and the lenses are prescribed for regular wear at night.

The final improvement in vision after the first application does not occur. It takes about two weeks to become less by 2-3 diopters.

At first, the patient may be disturbed various disorders vision: glare from light sources, blurred and light images. Often such side effects long time do not go away, then you have to either select other OK lenses, or completely abandon OK therapy.

This type of contact lenses is designed for a year of operation, they must be stored in a disinfectant solution. About once every six months, you should visit an ophthalmologist for preventive purposes.

The use of OK lenses can cause complications that are typical for any type of contact correction: erosion, hyper- or hypocorrection, complications infectious nature. In the event of any unpleasant symptoms you need to contact a specialist immediately.

Microtrauma while wearing contact lenses

When wearing contact lenses, the cornea experiences daily stress, microtraumas appear on its surface, accompanied by pain symptoms, feeling foreign body in the eye, lacrimation and redness of the conjunctiva. To restore the tissues of the ocular surface, after injuries, as adjuvant therapy, products with dexpanthenol can be used - a substance that has a regenerating effect on tissues, in particular, eye gel Korneregel. It has a healing effect due to the maximum concentration of dexpanthenol 5% *, and the carbomer included in its composition prolongs the contact of dexpanthenol with the ocular surface due to its viscous texture. Korneregel remains on the eye for a long time due to its gel-like form, is easy to apply, penetrates into the deep layers of the cornea and stimulates the process of regeneration of the epithelium of the surface tissues of the eye, promotes the healing of microtraumas and eliminates the sensation of pain. The drug is applied in the evening, when the lenses are already removed.

The cost of oc-therapy

The OK-therapy procedure is a rather costly event, the cost of which in some cases can be half the cost of the vision procedure. This is easily explained, because its price includes the cost special studies, the time spent by a specialist on the selection of OK lenses, multiple visits to the doctor during the initial period of adaptation, which are necessary to obtain the best effect.

However, all these costs pay off, because OK lenses are designed for a very long period of use, and you do not often have to spend money on buying a new pair of lenses. In addition, sometimes good spectacle frame and high-quality lenses are also more expensive than surgical vision correction. And most importantly, you need to understand that orthokeratology is modern method correction of myopia, which allows you to do what you love, which would be impossible with spectacle or contact correction.