Corneal curvature: Doctor-medic Bányai explains the key values

With corneal astigmatism, the cornea has two different curvatures set at 90 degrees to each other. This causes light rays to refract at different strengths. Instead of a single focal point, this refractive error creates “focal lines,” resulting in a distorted image on the retina.

In medical terms, this is known as astigmatism, a word derived from Greek meaning “pointlessness.” Since no two cases of astigmatism are the same, cylinder values (CYL) must always be accurately determined and assessed to create an adequate treatment plan. In this article, you will learn more about the classification of astigmatism.

What is a “Normal” Value for Astigmatism?

The severity of this refractive error varies from person to person. Correction is typically recommended starting at 0.5 diopters, as uncorrected astigmatism can significantly impair visual performance.

Furthermore, the curvature is not always identical in both eyes. While regular astigmatism usually remains constant, irregular astigmatism can worsen significantly over the course of a lifetime. Depending on whether you also have nearsightedness, farsightedness, or presbyopia, positive or negative diopter values are used for correction.

Mild Astigmatism Values

We speak of “mild” astigmatism when the curvature is so slight that an ophthalmologist sees no immediate need for correction with specialized toric contact lenses or glasses.

Many people have mild astigmatism without even noticing it. Because the deviation is so small, there are usually no symptoms and visual acuity remains unrestricted. Patients in this category typically show values between 0.25 dpt and 0.5 dpt, which can be easily corrected with standard visual aids if necessary. The causes are usually genetic and cannot be prevented.

Severe Astigmatism Values

If a more pronounced form of astigmatism is present, those affected suffer from distorted and blurry vision at both far and near distances. Additionally, symptoms such as eye strain and headaches can decrease quality of life. This happens because the eye constantly tries to compensate for the blurred image by adjusting its refractive power.

Once astigmatism reaches 0.75 dpt or more, or if initial symptoms appear, your optician should adjust your contact lenses or glasses accordingly. If the value exceeds 2.25 dpt, it is considered a severe curvature.

Toric Lenses: In these cases, “toric” contact lenses or eyeglass lenses are used to correct the cylinder (CYL). It is essential to visit an optician or ophthalmologist at the first sign of symptoms to determine your cylinder value and identify any underlying refractive errors.

Astigmatism Test – Take the Online Vision Test Now

Would you like to know if you suffer from astigmatism, or have you been skeptical about your vision for a while? You can complete an astigmatism test quickly and easily online. This provides an initial indication of how urgently you should see an optician for a check-up.

Please note: Only a professional, on-site eye exam can provide accurate information about your eye health and the ideal treatment path.

Alternatively, schedule your personal consultation at one of our professional laser eye centers in Karlsruhe or Stuttgart today.