Astigmatism is a visual disorder. This is usually caused by the cornea if it is irregularly shaped. If the cornea is curved to different degrees, then the light rays entering the retina are imaged as a line. In people without visual impairment, the incident light rays are bundled to a point. The consequence of astigmatism is that objects both near and far are blurred or distorted . In many cases, this visual disturbance is accompanied by headaches and burning eyes. The usually congenital astigmatism is determined by the ophthalmologist, who examines the eyes and then determines the visual disturbance. However, it is not only a congenital visual disorder, but also one that can be acquired. Many of those affected are short-sighted and far-sighted at the same time.
Causes of astigmatism
The reason for astigmatism, also known as astigmatism, is usually a corneal curvature that is genetically determined . However, astigmatism can also occur after certain diseases and therefore does not have to be caused by genetic factors. In people without visual impairment, the cornea is normally almost perfectly spherical and therefore curves equally in all directions. Then rays of light are refracted on the cornea and hit the retina with pinpoint accuracy. However, a crooked cornea breaks the light rays to different degrees, which is why they can no longer be bundled into one point on the retina. The result is an image as a line or as a rod, which is why we speak of astigmatism. However, a crooked cornea is not always the reason for astigmatism, as the lens or even the back of the eye can also become crooked. However, this is rarely the case. If astigmatism is not a genetic inheritance, astigmatism can also have other consequences. For example, if the upper eyelid presses too hard on the cornea, it can also curve. Scars and various diseases can also damage the cornea and can lead to a curvature. Even clouding of the cornea, which often occurs in cataracts, can be a reason for astigmatism. Different strengths of such astigmatism are also differentiated, since this is not the same in every affected person.
Symptoms of this visual impairment
The first signs of astigmatism are often burning eyes and severe headaches . In addition, vision is blurred both near and far – in contrast to nearsightedness or farsightedness, where vision is blurred either near or far. The aching eyes and headaches are explained by the fact that the lens is constantly trying to focus and is therefore very strained. Many sufferers who have only mild astigmatism do not notice any symptoms at all. Such symptoms can only be observed with a stronger visual disturbance. In addition, it can be said that visual performance usually does not deteriorate further in the case of astigmatism. An exception to this is children, since their eyesight can deteriorate quite significantly.
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