What are the types of astigmatism? How can this disease be detected? You will find answers to these and other questions in the article. Astigmatism is a disorder of refraction (refraction of light), in which the image is focused not in one, but at once in several points of the retina. This is due to the incorrect shape of the cornea.
Together with farsightedness and nearsightedness, astigmatism refers to ametropia. These are conditions caused by incorrect refraction. It should be noted that astigmatism is a very common pathology, which, according to various sources, occurs in 25% of the total population. Consider the types, stages, symptoms and correction of astigmatism below.
What is this?
What is astigmatism? It is one of the main causes of vision loss. In fact, astigmatism is a transformation of the standard refractive power of the transparent spheres of the eye, in which its weakening (hypermetropic astigmatism) or strengthening (myopic astigmatism), as well as a pronounced disorder of sphericity, can be observed. In this case, as a rule, the refractive power insome meridians have more than others.
With such a violation, a person cannot choose the optimal distance to the object in order to clearly see it. The distance in one meridian for the refraction of light rays may be adequate, and in the other - inadequate.
Causes of astigmatism
Few people know the symptoms, causes, signs and types of astigmatism. This disease develops due to the incorrect shape of the cornea (sometimes the lens). The word "astigmatism" is translated from Latin as "lack of a focal point."
It is known that the lens and cornea of an intact eye have a spherical flat surface. With astigmatism, this sphericity is disturbed, and as a result, different curvature is formed in different directions. Different meridians of the surface of the cornea in this state have different refractive power, so the picture of an object during the passage of light rays through such a cornea is distorted.
Some areas of the image are projected onto the retina, others behind or in front of it. But there are situations that are more complex. As a result, a person sees not an ordinary picture, but a transformed one, in which some lines are clearly visible, while others are blurred. How do people with astigmatism see objects around them? Take an oval teaspoon and look into it. You will see your reflection distorted in it, and this is how people with astigmatism see everything around.
Symptoms
Types of astigmatism we will considerFurther, and now we list the symptoms of this disease. These include:
- Headache.
- Blurry vision that does not depend on distance.
- Deformation of straight lines.
- Relentless eye strain.
- Rapid fatigue of the organs of vision.
Views
The disease is classified based on certain factors. According to them, the following types of astigmatism are distinguished:
- by reason of appearance - acquired, congenital;
- on pathology - lens, corneal;
- by type: with oblique axes - straight, reverse;
- according to the source of refractive power - incorrect, correct;
- in appearance - complex, myopic, simple;
- hypermetropic - mixed, simple, complex.
It is known that the human eye is a structure that perceives not the object itself, but the light reflected from its surface. The radiation falls on the retina, from which information is sent via the optic nerve to the brain, where the final picture is formed. But before that, the light goes through a clever mode of refraction.
Each point of the object reflects rays of light, which are first refracted in the cornea and enter the lens through a watery substance. Then, through the lens, the rays are sent to the vitreous body, refracted again, and after that they end up on the retina.
The order of refraction of light rays and the intricate structure of the eye determine a large number of variations of this disease.
Astigmatismacquired and congenital
Agree, the types of astigmatism are not so easy to study. The congenital form of this disease is the most common, which is determined by pathological processes at the time of laying the organs of vision of the fetus in the early stages of pregnancy. Congenital astigmatism is usually inherited from parents. That is why it begins to develop at an early age.
If mom or dad suffers from this disease, the baby should be checked for the presence of the disease as early as possible, because it can progress.
Those children whose vision is not focused often squint, tilt their heads to one side, roll their eyes together, and so on. If timely treatment is not prescribed, such methods of correction can lead to the development of persistent strabismus. It will persist even when you remove the root cause.
Everyone should know the classification of astigmatism types. Congenital astigmatism is pathological and physiological. In the second case, the refractive differential in the principal meridians is minimal. Inconspicuous astigmatism of 0.5 diopters is associated with the progressive growth of the eyeball in babies, which causes negligible deformation. And even astigmatism of 0.75-1 diopter does not affect the visual function of the eye.
If the abnormal refraction exceeds one diopter, the condition is pathological, accompanied by a decrease in visual acuity and needs special treatment.
Congenital astigmatism harms a person much more than acquired with age. After all, a child from the first days of life perceives the pictureincorrect, which leads to a h alt in the development of the visual apparatus as a whole.
Acquired astigmatism is not associated with physiological processes in the body and congenital pathology, so it can appear at any age. The disease evolves under the influence of external causes that have led to defects in the lens or cornea. It may appear due to the following factors:
- Acute keratoconus - an ailment of the cornea, as a result of which it becomes thin and takes on a conical shape.
- Injuries - damage to the eye by sharp or cutting objects, subluxation of the lens, ruptures of its ligaments.
- Keratitis - inflammatory processes in the cornea, which are the result of infection, physical impact or penetration of chemical substances, resulting in a violation of the integrity of the cornea and bending it.
- Difficult childbirth - the imposition of forceps on the head of the fetus, squeezing, causing deformation of the eyes and orbits.
- Pathologies of the dentoalveolar system - such ailments of the upper jaw and teeth, leading to deformation of the orbits, such as protrusion of the upper jaw forward, open bite, and so on.
- Surgical treatment of the eyes can provoke the development of induced astigmatism. So, if the doctor pulled the seams on the wound of the cornea too tightly, its shape can change significantly. The early removal of sutures has the same effect, when the edges of the incision diverge against the background of increased intraocular pressure.
Lenticular and corneal
We continue to study the types of astigmatism further. cornealastigmatism (corneal) appears due to tuberosity on the surface of the cornea, its uneven curvature. Moreover, the bending of the aspherical cornea in the vertical direction, as a rule, is stronger, and as a result, the rays of light are refracted more than in the horizontal direction. This species can either be acquired (after suffering ailments and injuries) or inherited (be congenital).
Lenticular astigmatism is much rarer. The cause of this disease is mainly a hereditary factor. It is characterized by asymmetry of the lens or its placement relative to the anteroposterior center of the eye. The sources of acquired astigmatism are:
- senile cataract, in which the layers of the lens swell;
- injuries (displacement of the lens, contusion of the eye, which is accompanied by clouding);
- diabetes mellitus (an increase in blood sugar provokes organic changes in the lens).
Reverse and direct
Let's analyze the following types of eye astigmatism. The types of this disease are determined by the power of light refraction (refraction) in the base meridians. If a more significant refractive reserve has a vertical meridian, this is direct astigmatism. With this type, vertical lines are captured more clearly. With age, direct astigmatism transforms into reverse.
Reverse astigmatism is a violation in which the horizontal meridian has the limiting refractive capabilities. Hence a different name appeared - horizontal astigmatism. This disease rarely develops. Since the outside world has a vertical orientation, astigmatism of the reverse type causes discomfort, inconvenience.
There is another variation - astigmatism with oblique axes, when the meridians with the limiting and least refractive power do not pass along the vertical or horizontal axis, but along an oblique, away from them.
Wrong and right
Any ophthalmologist can tell you about the types, types and correction of astigmatism. But it is better if you study these nuances yourself. Correct astigmatism is characterized by an elliptical outline of the eyeball. It occurs more often than other variations, as it is a congenital threshold of the cornea. Light passing through the elongated axis of the oval will be refracted less, and going through a short meridian - as much as possible.
Over time, in 50% of cases, the disease either increases or decreases. Moreover, the possibility of one or another development is almost identical. In other cases, the disease does not change its form. Such modifications are associated with the natural development of the organs of vision, their activities during the growth of the baby.
In the meridians directed in different directions, with this type of illness, the refraction of rays occurs either strongly or weakly. But the power of refraction in each of them is identical along the entire length.
At the same time as the different curvature of the main meridians, irregular astigmatism is determined by the fact that the same meridian is refracted differently in different areas.
This type of ailment affects those who have undergone surgery, injury oreye diseases. These people have reduced visual acuity, severe headaches appear during visual stress, the objects in question are transformed, bifurcated.
Unfortunately, irregular astigmatism, as it is also called, cannot be treated. In this case, the optical correction does not bring the desired result either. This is the very precedent when the disease is easier to prevent than to cure.
Hyperopic and myopic
Carefully study the types and treatment of eye astigmatism, and then you can always prevent this disease. What is myopic simple astigmatism (nearsighted)? This is a condition when some rays, after passing through the refractive structure of the eye, are collected on the retina, while others are in front of the retina (myopic focus). The greater the distance between the focuses, the greater the degree of violation, the more blurry the picture will turn out.
It is known that astigmatism of 1 diopter with a vertical enhanced meridian does not cause complaints of decreased vision. That is why it is of the physical type.
Myopic complex astigmatism is a condition when refracted light is collected in front of the retina at many points at an unequal distance from it, that is, myopic disorders are found in two meridians at once. This deterioration may occur due to the following reasons:
- Acquired (formations on the cornea of a scar due to ailments, trauma, surgery, less often - a pathological form of the lens).
- Congenital (hereditary distortion of the cornea).
Hypermetropic astigmatism bythe mechanism of appearance is identical to the myopic one. Here the difference is that farsightedness (hypermetropia) is a type of refraction when the focus is behind the retina, and not in front. Violation is complex and simple, acquired and congenital.
Mixed astigmatism
Now consider mixed astigmatism. What does he represent? Mixed astigmatism is a condition when two types of this distortion of vision are combined: the rays of one meridian form a focus behind the retina (hypermetropic type), and the other in front of the retina (myopic type). With this pathology, any picture is perceived as deformed, it is almost impossible to visually identify the size of the object, the distance from it.
The most severe form of visual impairment is mixed bilateral astigmatism, which is usually accompanied by late development of the visual organs and strabismus.
The higher the degree of the disease, the more difficult it is to heal. Therefore, it is important to detect vision pathology in time, since the sooner correction and treatment measures are prescribed, the more chances they have for success.
How to treat?
Astigmatism can be cured. There are such temporary methods of correcting vision, allowing the patient to lead a typical lifestyle until complete recovery:
- Contact lenses. To correct astigmatism, special contact toric lenses are used, which do not cause inconvenience while wearing, unlike glasses.
- Point correction. For astigmatism, the patient should wearspecific glasses with lenses in the form of a cylinder. Before their selection, a person undergoes a special diagnosis. Experts say that wearing glasses in people with a high degree of astigmatism can cause dizziness, pain in the eyes, and visual discomfort.
However, wearing contact lenses or glasses can correct vision only temporarily. You can permanently get rid of the disease with the help of laser vision correction (Lasik), which has recently been used more and more often to treat astigmatism.
Prevention
What is the prevention of astigmatism? It consists of the following nuances:
- Compliance with the regime of visual, physical activity. Visual tension must be alternated with active rest.
- Compliance with the correct lighting regime. The workplace should be well lit.
- Using vitamins with lutein.
- Performing gymnastics for the eyes. Every 20 minutes during eye strain, you need to perform gymnastics for the organs of vision.
- Treatment of eye ailments that affect the development of astigmatism.
- Relieve eyestrain and improve blood circulation in the eyeball and its surrounding tissues. This can be done with the help of physiotherapy massage - color therapy, pneumomassage and so on. All these features are implemented in the device "Points of Sidorenko".
It is important to remember that the prevention of astigmatism is very important. Strictly speaking, astigmatism is not an ailment, but a "mistake" of the eye. However, this does not meanthat he is safe. Complex diagnostics and treatment can be done in many ophthalmological clinics. When choosing a medical institution, consider not only the cost of treatment, but also the reputation and level of the clinic's specialists.
Astigmatism in babies
Different types of astigmatism in children appear much more often than is commonly believed. So, 40% of schoolchildren have a weak degree of astigmatism, and 6% have a strong one. This pathology not only causes inconvenience to the baby, it is also fraught with the development of myopia and a decrease in school performance. Therefore, it is very important to detect this problem in time and start treatment.
A child suffering from any kind of astigmatism (simple, complex, mixed, and so on), as a rule, does not complain about vision because he has always seen it this way and does not know that it is wrong. This fact complicates the current diagnosis. Astigmatism in babies is usually detected at an appointment with an ophthalmologist. Therefore, show your child to a doctor from the age of 2 months and, if this ailment is detected, visit this specialist every six months. And stay he althy!
