Astigmatism

Astigmatism is a common refractive error in which the cornea or the lens of your eye is not uniformly curved. In an eye without astigmatism, the cornea is perfectly round, like a football. With astigmatism, the cornea is more oval in shape, similar to a rugby ball. As a result, rays of light are not focused at a single point on the retina, but at multiple points or along multiple lines. The result is that your vision is blurred, distorted or double, both at a distance and up close.

Astigmatism is expressed in terms of cylinder (cyl) and axis. The cylinder indicates the strength of the astigmatism in dioptres, whilst the axis indicates the direction of the curvature, expressed in degrees between 0 and 180. You will find these values on your spectacles prescription or contact lens prescription, often listed as ‘cyl’ and ‘axis’ or ‘ax’.

The cause of astigmatism is usually congenital and hereditary, but it can also result from scarring of the cornea, an eye injury or an eye condition such as keratoconus. Astigmatism often occurs alongside short-sightedness or long-sightedness.

How do you recognise astigmatism?

People with astigmatism often experience blurred or distorted vision, both at a distance and up close. Letters may appear stretched or slanted, and lines may look distorted. Headaches, tired eyes and difficulty seeing clearly in low light are also common complaints. Mild forms of astigmatism sometimes cause few symptoms, as your eyes partially compensate for the difference by squinting or focusing more intently, which can actually lead to eye strain.

Correction with contact lenses

Astigmatism can be corrected with special contact lenses known as toric lenses. These lenses have a built-in cylindrical correction and are designed to remain stable in your eye, ensuring the correction stays in the correct position. Toric lenses are available as soft daily disposable lenses, monthly lenses and also as rigid lenses. At SMEYEL , you’ll find a wide range of contact lenses for astigmatism, for both consumers and opticians.

When should you visit an optician or ophthalmologist?

If you are experiencing blurred vision, headaches or tired eyes, have an eye test carried out by your optician or optometrist. Astigmatism is diagnosed through a refraction test, during which the degree and axis of the condition are accurately determined. In the case of young children or sudden changes in your vision, it is advisable to see an ophthalmologist.