Cylinder in the eye (astigmatism)

Diagnosis of astigmatism in the eye is performed in an examination by an ophthalmologist, usually in a simple vision test that examines the focusing ability of the eye. Astigmatism is usually corrected conservatively by means of a cylinder lens or multifocal lenses. In certain cases, contact lenses can also be used to treat astigmatism. One can also undergo a surgical procedure to treat astigmatism in the eye.

What is astigmatism?

Astigmatism describes a condition in which the cornea of the eye is not perfectly spherical, but takes on a more elliptical and cylindrical shape – therefore, this condition is also called "cylinder in the eye". As a result of this structural change, the light rays are refracted abnormally as they enter the cornea, and several focal points are obtained on the retina of the eye instead of one focal point. That is, astigmatism causes a distortion of the light rays reaching the eye and thus blurred vision.

Causes of astigmatism

Astigmatism is a relatively common condition in the population, and it is estimated that about 40% of people suffer from it. The possible causes of the development of astigmatism or cylinder in the eye are mainly genetic, due to which the phenomenon usually appears at an early age. Additional causes of cylinder can also be injury or various infections in the eye area, as well as changes in the shape of the cornea after eye surgery. In addition, keratoconus disease also causes the development of cylinder in the eye, since in this disease the cornea of the eye takes on the shape of a cone and the way the light rays are refracted changes. Likewise, the shape of the lens may change at an older age or as a result of the growth of a pterygium in the eye.

Types of astigmatism in the eye

Cylinder in the eye is characterized by a size and an angle that determine the degree of correction required. These two measures vary according to the shape of the lens and according to the cause of the astigmatism. For example, there may be a situation in which there is a "regular" cylinder when the lens is elliptical but symmetrical, or a situation in which there is an "irregular" cylinder when the lens does not have equal curvatures and is not symmetrical. The spectrum of cylinder in the eye can range from mild astigmatism (low cylinder) that causes a "smearing" of distant text to severe astigmatism (severe cylinder) in which this "smearing" is sharper and is obtained already in near vision.

Signs of astigmatism

Astigmatism can lead to varied signs of disturbed vision. Among other things, a state of cylinder in the eye may lead, as noted, to blurred vision, "smearing" of lights in the evening hours and glare from them and even spots in the field of vision. Likewise, cylinder in the eye may cause fatigue, headaches and concentration problems.

In the case of cylinder in the eye in children, identifying the signs is challenging. This is because children are usually not aware that their vision is abnormal and therefore will not report a disturbance in vision. Therefore, if squinting, frequent eye rubbing or headaches are identified – one should go and be examined by a children's ophthalmologist.

Diagnosis of astigmatism

Diagnosis of cylinder in the eye is performed in an examination by an ophthalmologist, usually in a simple vision test that examines the focusing ability of the eye. In addition, one can undergo an examination by a keratometer that computes the various curvatures in the cornea of the eye, and thus produces measures regarding the cylinder.

Complications of astigmatism

Cylinder in the eye is a dynamic condition affected by many factors (mainly external ones). Therefore, in certain cases such as in children, the degree of cylinder can be improved significantly. Treatment at an early stage of cylinder can prevent the development of a lazy eye. However, for the most part, most people with cylinder in the eye actually suffer from a worsening of the condition over time.

Treatment of astigmatism

Astigmatism is usually corrected conservatively by means of a cylinder lens or multifocal lenses. In certain cases, contact lenses can also be used to treat astigmatism. A cylinder lens is a lens that is not spherical in shape but has different curvatures. This structural change neutralizes the distortion of the cornea and allows the light rays to be refracted more normally, thus improving vision while providing a more comfortable and aesthetic solution. Likewise, one can undergo a surgical procedure to treat cylinder in the eye. As part of the surgery, the cornea of the eye is re-shaped and re-polished by means of a laser.

Summary

From the above, cylinder in the eye is a condition that causes impairment of vision. It stems from various factors and manifests in different forms. However, there are varied treatments for treating astigmatism that allow individual matching to the patient.