People diagnosed with astigmatism know firsthand how the correction of optical devices is performed. Various methods are used to correct this disease. The selection and recalculation of astigmatic lenses is performed by an ophthalmologist familiar with the patient's vision. This disease affects the eyes in different ways, so for each you have to select different diopters and polarities. In order to improve vision, lenses are recalculated.
What is astigmatism
From Latin, the concept of "astigmatism" stands for lack of focus. Pathology is acquired and congenital. An anomaly of refraction is characterized by the fact that the rays that enter the eye are at several points. Because of this, images cannot focus on the retina, but only behind or in front of it. There is a distortion of the visible, blurring, splitting in the eyes.
Astigmatism refers to visual pathologies that are very difficult to recognize at an early stage. This is what distinguishes it frommyopia and farsightedness. The patient has an uneven refraction of light rays in different parts of the lens and cornea. Therefore, it is much more difficult to correct vision with such a diagnosis.
Signs of disease
Physiological astigmatism, which is obtained in a hereditary way, is much more difficult to identify. Often a person, even in childhood, gets used to a slight blurring of objects and does not even notice this effect. This type of disease can pass in adolescence. Only in rare cases does it lead to the development of complications, so it does not require correction.
If tangible unpleasant symptoms appear, then pathological astigmatism develops. It is characterized by the following features:
- distorted vision of objects;
- asthenic manifestations;
- rapid eye fatigue;
- deterioration of visual acuity.
With astigmatism, the patient develops a habit of squinting his eyes strongly, as if sharpening, pulling the skin of the eyelids in the corner of the eye, trying to better examine objects. He tries to shift the focus so that it is closer to the retina. Despite the fact that these actions lead to headaches, discomfort, pain in the eyes, it is impossible to see the surrounding objects in a different way.
If the pathology remains untreated for a long time, then a person develops accommodative strabismus, which often leads to irreversible consequences. This phenomenon can occur even in a child after 2-5 years, so it is recommended to regularlytest visual acuity even in children.
Diagnostic Methods
Usually, the diagnosis of astigmatism is based on the patient's complaints. After that, the doctor prescribes procedures that include skiascopy, examination of visual acuity and refraction, and biomicroscopy. It is also necessary to measure intraocular pressure after using special drops.
Syascopy is the most affordable way to perform a diagnosis. It has been used for a long time by many professionals. Siascopy in just a few minutes helps to measure refraction in different meridians, to establish the degree, type and type of astigmatism. There is another, more modern method for determining refraction - refractometry.
To diagnose and clarify corneal astigmatism, procedures such as computed keratotopography and ophthalmometry are suitable. Due to the fact that the cornea does not have a perfectly round shape in the disease, it is very difficult to measure the degree of vision. And these techniques help to identify the deviation of the cornea from the norm and determine what kind of irregularities it has.
How lenses are selected
Many patients with this pathology are interested in whether it is possible to use lenses with astigmatism. Ophthalmologists answer this question positively, emphasizing the advantages of contact devices over astigmatic spectacle lenses. In this disease, a special toric optics is used. It is highly accurate and suitable for people of all ages. However, in order toto achieve a positive effect, you need to choose the right optics.
When selecting lenses, an ophthalmologist must take into account the various nuances of a person's lifestyle, which include:
- driving a vehicle;
- field of activity;
- presence of any sport;
- activity level.
The patient's activity matters a lot. If every day he has to work at the computer, getting a huge load on his eyes, this must be taken into account when choosing and quickly recalculating the diameter of the lenses. These optical devices have several varieties.
When you need to recalculate astigmatic lenses
Transposition - the process of calculating the value of diopters. It consists in the selection of lenses when the patient's eyes see differently. This procedure is performed according to a special algorithm. It is not recommended to do the transposition of astigmatic lenses on your own, as this can lead to visual impairment. The ophthalmologist will not only prescribe procedures for checking indicators, but with the help of special devices will be able to choose the right type of optics.
Medical abbreviations
After all checks are completed, a prescription for lenses is issued. Abbreviations of Latin names are used for brevity. Knowing the transcript, the patient will be able to read the prescription and find out which astigmatic lenses he was prescribed. The following symbols are found on the patient's discharge:
- OU - indicators of both eyes;
- OS and OD- left and right eye;
- DP - an indicator of the distance from one pupil to another;
- D - the number of diopters (with farsightedness, a plus is added near the reduction, with myopia - minus);
- AX - the tilt required to install a cylindrical lens, the indicator is indicated in degrees;
- CYL is an abbreviation for a cylinder lens. There is always a number of diopters nearby;
- SPH - short name for spherical lens;
- ADD - add (diopter gain in a certain part of the lens).
The last cut is very important. Addition indicates the need to increase the diopters in the lower or upper part of the spherical optics. This option improves visual sharpness depending on the viewing angle. Addition began to be done relatively recently, therefore, the reduction occurs only occasionally. Knowing how to decipher the designations and knowing how the astigmatic lenses are recalculated, it will be easier for the patient to determine the type of optics.
Varieties
The selection process for astigmatism is complicated by the fact that conventional lenses are contraindicated for the patient. They are specially selected, since simple ones will constantly shift, distort the image. Recalculation of astigmatic lenses allows them to take the desired position, thereby attaching to the surface of the cornea. There are the following varieties of this optics:
- Soft. Appeared not very long ago. It looks like a film that follows the shape of the cornea. This lens is invisible to the eye and provides comfortable wearing. Thanks to thesequalities, patients prefer this type of rigid optics.
- Tough. It consists of polymers that allow air to freely penetrate to the cornea. Holds its shape well and is suitable for long-term wear. However, due to the rigid structure of the adaptation of the eye, it takes a long time to adapt to new sensations. It has a number of contraindications for use.
Soft astigmatic lenses belong to the category of modern developments. Recently, they are preferred by more patients. Unfortunately, when wearing these lenses, astigmatism will be felt more strongly due to the fact that they are thin, tightly attached to the cornea and follow all the bumps.
In order to choose the appropriate type of optics, you need to take into account individual indicators and the advice of a doctor. In some cases, it is recommended to simply try both varieties to see which one is the most comfortable. Both hard and soft lenses need to be properly maintained by disinfecting them. Special drops are prescribed for the eyes so that inflammation does not appear from the constant wearing of optics.
Benefits
Indicator of the correct selection of astigmatic lenses is the absence of discomfort during their application. Most patients see only benefits while wearing optics. The advantages of such lenses include:
- ensure a wide viewing angle;
- option to choose colored astigmatic lenses;
- eliminate prism effect;
- great choice for different types of astigmatism;
- minimal image distortion;
- quality materials, safe for the eyes.
If the blurring of the image after applying the optics has completely disappeared, then the lenses are chosen correctly.
Flaws
The negative effects of astigmatic lenses appear after wearing them for a long time, so doctors recommend not only choosing optics, but resorting to methods of treating the disease. The list of disadvantages includes:
- frequent inflammation of the retina;
- optical distortion;
- development of myopia;
- presence of individual contraindications;
- change in topography.
These disadvantages must be taken into account at the stage of transposition and selection of astigmatic lenses, so as not to worsen the overall situation.
Materials for making
The safety of this optics is explained by the fact that in its manufacture different manufacturers use modern safe materials. The most common raw materials are hydrogel and silicone hydrogel. These materials do not cause allergies in most people, they are perfectly perceived by the cornea. When applied correctly, they do not adversely affect the eyes.
Reviews
After wearing special optical devices designed for patients with this disease, one feels how comfortable they are. Therefore, people who use astigmatic lenses describe their positive experience in the reviews.
Preference is given to opticslong-term use, which does not need to be changed daily. It costs more, but it is much easier to care for it.
Conclusion
Even with the correct selection of astigmatic lenses, the disease does not go away, the refractive error does not become smaller. That is why ophthalmologists recommend establishing the cause of astigmatism and undergoing treatment. If there are no contraindications, then there are different methods of therapy to cure the pathology. These include many ways (from gymnastics to train the eyes to surgery).
