Myopia, better known as myopia - this is a condition of the eye in which close objects seem to be clear, but at a distance everything is seen becomes blurred and focus is lost.
In order to stop the development of myopia in children in time, ophthalmologists around the world are actively introducing the use of glasses. with perifocal lenses, which, if properly prescribed, can not only slow down the growth of myopia, but also cure her.
Numerous studies in the field of ophthalmology have shown that conventional monofocal glasses and contact lenses, which have been prescribed for years to correct myopia throughout childhood, can increase the risk of developing myopia, along with its other causes - such as: congenital defects of the eyeball, excessive eye strain, chronic and infectious diseases, injury.
Now every second graduate of the school has vision problems.
According to the scientific forecast voiced at the congress in the UK - by 2050, 50% of the world's inhabitants will be myopic, therefore it is especially important that the parents of schoolchildren (it is especially important visit an ophthalmologist at the age of 6-9 years) monitored the development of vision of their children and took the necessary measures in a timely manner in case of problems, which they successfully cope with perifocal glasses.
Record content:
- 1 Peculiarities
- 2 Research
- 3 Types of lenses
- 4 Types of coatings
- 5 Application
- 6 Top manufacturers
- 7 Rates
- 8 Video about perifocal glasses
Peculiarities
The principle of operation of a perifocal lens is to bring the eye as close as possible to the natural perception of the surrounding world. This is a lens that has a stable optical index in the center, which changes its numbers towards the periphery (edges). For example - in the center of the lens there may be a -3D index, which gradually decreases towards the edges (horizontally) to -2D.
Thus, the light load is evenly distributed over the entire surface of the retina of the eyeball. This is the main difference from standard optics, which strictly affects the central part of the eye, which is why peripheral vision is often impaired. When using such lenses, the progression of myopia stops, and in many cases is completely cured.
The diopter range for the Perifocal lens is wide enough:
| Refractive index | Diopter range | Astigmatism (cylinders) |
| Up to 1.6 | from -13.5 to +5.0 | until 6 |
| 1.6 and more | from -13.25 to +6.0 | until 6 |
Research
For a long time, eye care professionals and scientists have been interested in slowing and stopping the growth of myopia. And a number of recent studies show that it is indeed possible to control myopia by slowing its growth during childhood.
The first perifocal glasses for stopping myopia in children were developed in 2011. renowned specialist in the field of optical lens modeling, Professor Jose Alonso (Complutense University, Madrid).
Clinical study of the effect of perifocal glasses on axial and peripheral refraction (the process of refraction of light rays in optical system of the eye) in patients with myopia, which was carried out in 2013 - 2014 by the Eye Research Institute named after
Helmholtz of the Ministry of Health of Russia, revealed and confirmed the multifactorial effect of the perifocal lens. Glasses with progressive myopia help stabilize refraction or significantly slow down negative processes.
The high efficiency of Perifocal lenses in affecting the growth of myopia is noted. According to the results of studies that were carried out at the Eye Research Institute.
Helmholtz, it was revealed that during 4 - 5 years of using perifocal glasses in children, the growth rate of myopia decreased from the initial 0.8D to 0.17D, and their use was 60% more conducive to stopping the growth of myopia in comparison with the control group of children wearing monofocal glasses.
Also in 2014, a retrospective analysis of data from 46 children aged 7 to 12 years with myopia from -1.0D to -3.75D, which showed that wearing perifocal glasses for 12 months reduced axial refraction or showed no development myopia.
The Skolkovo Foundation and the Russian-American company Novamedika carried out international expertise, and Perifocal optical lenses were approved by specialists.
Types of lenses
Perifocal glasses for stopping myopia in children are divided into 3 main types according to the type of lenses:
| Perifocal M | Perifocal h | Perifocal P |
| Corrects myopia or stops its growth. Recommended for children and young patients with an increase in myopia. The effect is achieved by slowing down the growth and equalizing the size of the eyeball. | Originally designed for children with congenital farsightedness. With this disease, the eyeball has a smaller (compared to the standard) size. In the process of wearing perifocal glasses, the eyeballs begin to grow in length, and the deviations disappear. Over time, Perifocal H was also prescribed for adult patients with acquired hyperopia. | For permanent or temporary wear as a prophylaxis for the onset of myopia. It is prescribed for patients with a hereditary predisposition or those whose eyes are subject to high stress. Recommended for patients with normal vision, but whose eyes lose the ability to focus on objects located at different distances. |
In addition, on the Russian market, the company "ArtOptics" presents modifications main types of Perifocal lenses with enhanced optical properties:
- Perifocal-Ms;
- Perifocal-Msa;
- Perifocal-Ps;
- Perifocal-Psa.
The additional designation "s" indicates an earlier onset of changes in diopter values by horizontal and more saturated values in relation to the center of the lens as it is done in the standard Perifocal. This allows you to increase the therapeutic effect in the treatment of progressive myopia.
Types of coatings
-
Crizal Easy UV Is the foundational coating in the Crizal range. Protects from scratches, smudges and fingerprints. Perfectly protects against UV radiation;
- Сrizal Forte UV - This coating has ideal water-repellent qualities, increases durability, eliminates the lens from getting scratches, staining with dirt, grease and fingerprints. This coating guarantees maximum transparency and contrast of the lens, protects against UV radiation;
- Crizal prevencia - the coating has all the properties of Crizal Forte UV plus additional protection against dangerous blue-violet radiation.
Application
Perifocal glasses stimulate the visual apparatus more gently, improving the ability of the eyes to sharply focus on objects. They do not require constant wearing, especially at the beginning.
At first, 40 minutes to 2 hours a day is enough, but for a tangible result it is recommended to wear them constantly. These glasses are used not only to correct and stop myopia and hyperopia, they help relieve eye spasms and improve accommodation.
One of the most important conditions for the correct selection of perifocal glasses for stopping myopia in children is the correct diagnosis. It is necessary to take into account all the nuances.
The first step is a complete ophthalmological examination:
- setting the exact degree of myopia (hyperopia);
- measurement of intraocular pressure;
- state of accommodation;
- the presence of complicating moments (astigmatism);
- condition of the oculomotor apparatus;
There are also a number of contraindications for prescribing glasses with perifocal lenses:
- glaucoma;
Perifocal glasses for children are contraindicated in glaucoma - strabismus;
- deviations in the vestibular apparatus;
- mental disorders.
After fitting the lenses and when the prescription has been written out, the patient selects the frame and proceeds to the usual wearing of glasses, for the first time it is possible to alternate the perifocal glasses with their usual, with ordinary lenses.
Top manufacturers
The world leader in the production of spectacle and contact lenses Perifocal remains one of the world's leading manufacturers of optical lenses Essilor (France). This company is engaged not only in production, but also in research activities (three of its own research centers). They were the first to enter into a contract with the creator of the perifocal lens, Jose Alonso.
Also "R.O.S. Optics ", which is a subsidiary of ArtOptics LLC, which has been a resident of the Skolkovo Foundation since November 2011, has started its own production of perifocal lenses.
Currently, only these two manufacturers produce original Perifocal lenses, you need beware of counterfeits, which not only will not have therapeutic properties, but can also harm vision.
Rates
Prices for Perifocal lenses are significantly higher than other types of spectacle lenses, but if you calculate the costs of standard treatment for progressive myopia - ordinary spherical glasses, visits to to an ophthalmologist, hardware treatment, eye drops and much more, it turns out that perifocal glasses really save time and money, and besides, it is constant preventive care child at home.
There is a wide variety of coatings for perifocal lenses on the market today. Considering the initially high price of the Perifocal lens, it is advisable to protect it from damage by applying a high-quality coating.
The prices for perifocal spectacle lenses, as well as for ordinary spherical lenses, except for additional charges for coating, depend on the refractive index, the higher the index, the thinner the lens. When moving from one index to the next (for example, from 1.50 to 1.60), the price, on average, doubles.
Perifocal lenses are made from glass, polycarbonate, polymer and photochromic polymer, which also affects the price of the finished product:
| The name of the lenses from the manufacturer Essilor (France) | Material | Coating type | Refractive index | Price (for one lens), rub. |
| Perifocal orma | Glass | Without cover | 1,5 | 5000-5500 |
| Crizal Easy UV | 1,5 | 6250-6950 | ||
| Сrizal Forte UV | 1,5 | 7500-8300 | ||
| Сrizal Prevencia | 1,5 | 8000-8800 | ||
| Perifocal Airwear polycarbonate | polycarbonate | Crizal Easy UV | 1,59 | 9550-11150 |
| Сrizal Forte UV | 1,59 | 10800-12450 | ||
| Сrizal Prevencia | 1,59 | 11300-12950 | ||
| Perifocal Ormix Crizal | polymer | Crizal Easy UV | 1,61 | 10000-10700 |
| Сrizal Forte UV | 1,61 | 11200-11950 | ||
| Сrizal Prevencia | 1,61 | 11750-21450 | ||
| Perifocal stylis | polymer | Crizal Easy UV | 1,67 | 13125-14600 |
| Сrizal Forte UV | 1,67 | 14375-15950 | ||
| Сrizal Prevencia | 1,67 | 14875-16450 | ||
| Perifocal Stylis Transitions Signature | Photochromic polymer | Crizal Easy UV | 1,67 | 20250 |
| Сrizal Forte UV | 1,67 | 21550 | ||
| Сrizal Prevencia | 1,67 | 22050 |
Perifocal glasses are an innovation in ophthalmology and the narrow choice of manufacturers contributes to high market prices.
But, confirmed by studies, the positive results of the effect of Perifocal lenses on stopping myopia in children suggest that the world's leading manufacturers of optics will expand the production of lenses of this type, which will reduce the price and this product will become more affordable for the end consumer.
Video about perifocal glasses
Do perifocal glasses help: