People with a diagnosis of astigmatism know firsthand how optical adjustments are made. Different methods are used to correct this disease. 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 choose different diopters and polarity. In order to improve vision, lens recalculation is performed.
What is astigmatism
In Latin, the concept of "astigmatism" stands for lack of focus. Pathology is acquired and congenital. The refraction anomaly 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, blur, bifurcation in the eyes.
Astigmatism refers to visual pathologies that are very difficult to recognize at an early stage. This is its difference from myopia and farsightedness. The patient has an uneven refraction of light rays in different parts of the lens and cornea. Therefore, correcting vision with such a diagnosis is much more difficult.
Signs of the disease
Physiological astigmatism, which is obtained by the hereditary method, is much more difficult to identify. Often a person, even in childhood, gets used to a small blur 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 correction is not required for it.
If tangible unpleasant symptoms appear, then pathological astigmatism develops. The following symptoms are characteristic of it:
- distorted vision of objects;
- asthenic manifestations;
- rapid eye fatigue;
- deterioration in visual acuity.
With astigmatism, the patient has a habit of narrowing his eyes strongly, as if directing sharpness, pulling the skin of the eyelids in the corner of the eye, trying to better examine objects. He tries to shift his focus so that he is closer to the retina. Despite the fact that these actions lead to headache, discomfort, pain in the eyes, a different view of the surrounding objects does not work.
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, therefore it is recommended to regularly check for visual acuity, even in children.
Diagnostic Methods
Usually the diagnosis of astigmatism is made on the basis of patient complaints. After that, the doctor prescribes procedures that include skioscopy, a study of visual acuity and refraction, biomicroscopy. It is also necessary to measure intraocular pressure after using special drops.
Syascoscopy is the most affordable way to perform a diagnosis. It has been used by many experts for a long time. In just a few minutes, siascopy 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.
Procedures such as computed keratotopography and ophthalmometry are suitable for diagnosing and clarifying corneal astigmatism. Due to the fact that the cornea does not have a perfectly round shape during 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 to choose lenses
Many patients with such a pathology are interested in whether it is possible to use lenses for astigmatism. Ophthalmologists answer this question positively, emphasizing the advantages of contact devices over astigmatic eyeglass lenses. With this disease, special toric optics are used. It is highly accurate and suitable for people of all ages. However, in order to achieve a positive effect, you need to choose the right optics.
When choosing lenses, an ophthalmologist must take into account the different nuances of a person's lifestyle, which include:
- driving a vehicle;
- field of activity;
- the presence of any sport;
- degree of activity.
The type of patient activity is of great importance. If every day he has to work at a computer, getting a tremendous strain on his eyes, this must be taken into account when choosing and quickly recalculating the diameter of the lenses. This optical device has several varieties.
When you need a recalculation of astigmatic lenses
Transposition is the process of calculating the magnitude 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 transpose astigmatic lenses on their own, as this can lead to visual impairment. An ophthalmologist will not only prescribe procedures for checking indicators, but also with the help of special devices will be able to choose the right kind of optics.
Medical abbreviations
After all the checks are completed, a prescription for lenses is written. For brevity, abbreviations of Latin names are used. Knowing the decryption, the patient will be able to read the prescription and find out what astigmatic lenses he was prescribed. The following indications 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 hyperopia near the contraction add plus, with myopia - minus);
- AX - the tilt that is required to install a cylindrical lens, the indicator is indicated in degrees;
- CYL - abbreviation for cylinder shaped lens. Nearby there is always the number of diopters;
- SPH is the abbreviation for spherical lens;
- ADD - addition (an indicator of the amplification of diopters in a certain part of the lens).
The latter reduction is very important. The addition indicates the need to make amplification of diopters in the lower or upper part of spherical optics. This option improves the sharpness of vision depending on the viewing angle. Addition began to be done relatively recently, therefore, reduction is only rare. Being able to decipher the notation and knowing how the conversion of astigmatic lenses occurs, 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 in the patient. They are specially selected, since the simple ones will constantly shift, distort the image. Recalculation of astigmatic lenses allows them to take the desired position, thereby - attached to the surface of the cornea. The following varieties of this optics exist:
- Soft. Appeared not so long ago. It looks like a film that follows the shape of the cornea. Such a lens is invisible to the eye and provides comfortable wearing. Due to these qualities, patients prefer this type of hard optics.
- Tough. It consists of polymers that allow air to freely penetrate the cornea. It maintains its good shape and is suitable for prolonged wear. However, due to the rigid structure of the device, the eye adapts to new sensations for a long time. It has a number of contraindications for use.
Soft astigmatic lenses belong to the category of modern developments. Recently, they are preferred by a larger number of patients. Unfortunately, when wearing these lenses, astigmatism will be felt more strongly due to the fact that they have a small thickness, are tightly attached to the cornea and repeat all the irregularities.
In order to choose the appropriate type of optics, you need to take into account individual indicators and doctor's advice. In some cases, it is recommended that you 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 from constant wearing of optics does not appear.
Benefits
An indicator of the correct selection of astigmatic lenses is the lack of discomfort during their use. Most patients only see benefits while wearing optics. The advantages of such lenses include:
- providing a wide viewing angle;
- the ability to choose colored astigmatic lenses;
- elimination of the prism effect;
- wide choice for different types of astigmatism;
- minimal picture distortion;
- quality materials, safe for the eyes.
If the blurriness of the image after using optics has completely disappeared, then the lenses are selected correctly.
disadvantages
The negative effects of astigmatic lenses appear after wearing them for a long time, so doctors recommend that you do not stop only at choosing optics, but resort to methods of treating the disease. The list of disadvantages includes:
- frequent inflammation of the retina;
- optical distortion;
- the development of myopia;
- the presence of individual contraindications;
- topography change.
These disadvantages must be taken into account even at the stage of transposition and selection of astigmatic lenses, so as not to worsen the overall situation.
Materials for the manufacture
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, are well perceived by the cornea. When used 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 using astigmatic lenses describe their positive impressions in reviews.
Preference is given to optics for long-term use, which does not need to be changed daily. It costs more, but looking after it is much easier.
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 that can cure the pathology. These include many methods (from gymnastics to train the eyes to surgery).