Astigmatism is an abnormality in the breaking ability of the eye, in which the two perpendicular meridians of the corneal surface are bent with different strengths. As a result, the image that is produced on the retina is unclear. Patients complain about blurred vision when watching near and far. Often there is a headache and a feeling of weight in the eyes. After overload, nausea and dizziness may occur.
Cause of astigmatism?
Most often, astigmatism is hereditary and is due to an abnormality in the corneal refractoriness. Another reason could be that the refractive power of the lens is impaired. Generally, for incorrect astigmatism there may be several reasons:
• Corneal trauma;
• Inflammatory corneal diseases (keratitis);
• Advanced keratoconus (corneal disease).
Risk factors
Astigmatism is a disease that occurs either by birth or during the progress of orgasm growth and the shaping of eyeballs.
• Children of parents who have astigmatism. But its development in such children is not necessarily;
• Nearsightedness and farsightedness – often accompanied by astigmatism;
Diseases affecting the cornea and disrupting its normal surface.
What are the illness changes in astigmatism?
The dioptric eye apparatus consists of several transparent and refractory elements: cornea, intraocular fluid, lens, and vitreous body. Each of the refraction environments has its own refractive index and different convex and concave boundary surfaces, resulting in a very complex optical system. The simplest cornea can be divided into a horizontal and a vertical meridian. Under normal conditions there is a slight difference in these two curvatures. Typically, the vertical meridian is more refractive than the horizontal with 0.5-1 diopters. When astigmatism is of this order, it is called physiological and no correction is needed with glasses. When these dioptres are larger, then it is a pathological astigmatism and it is necessary to correct it.
How is a diagnosis made?
Diagnosis of astigmatism is performed by an ophthalmologist.
The following methods are used to diagnose the disease:
• Automatic refractometry – measuring the refractive power of the eyes using a fully automated device. Relying on the accuracy of the results obtained by him;
• Keratometry – examines the surface and thickness of the cornea.
Treatment of asthmatism
Correction of astigmatism is done through glass – specular glasses, which only bend in one axis and in its perpendicular axis. When astigmatism is corrected with other refraction anomalies (farsightedness or shortsightedness) correction is performed by a combination of spherical (+ or -) and cylindrical glass. Incorrect astigmatism can be corrected by contact lenses.
