Astigmatism is an error in the curvature of the cornea. Instead of being spherical, the cornea is oval instead.
If you notice distortion or blurriness when looking at objects at any distance, whether they are far away or close up, you probably have astigmatism.
It is important to note that all individuals suffer from astigmatism to a minuscule degree, as no cornea is perfectly round. In those with astigmatism, the cornea is usually compared in shape to a rugby ball as opposed to the football-shaped cornea of an emmetropic eye (i.e. one without any visual defects). This affects the quality of perception of the image, which is focused not on a single point on the retina but on several different points, making both near and far-away objects appear blurry.
There are two types of astigmatism: ‘regular’ astigmatism, which is more common and is when the curvature of the cornea is more pronounced in one direction, and ‘irregular’ astigmatism, which occurs as a result of an injury or degenerative disease (keratoconus).
Generally speaking, astigmatism is a vision problem that is present from birth, and is usually more likely to occur if there is a family history of the condition.
You could be enjoying a new life without glasses or contact lenses. Make an appointment at the centre of your choice, Lausanne, Neuchâtel or Zurich. The first consultation is free.
Symptoms and treatment
In most cases, people are born with their astigmatism.
Symptoms can vary from one individual to another, but usually people with astigmatism have blurred or distorted vision and may suffer from nausea or headaches. Sufferers may also experience irritation or fatigue of the eyes and difficulty seeing at night.
There are several ways to correct this visual defect: glasses, specially adapted contact lenses referred to as ‘toric’ lenses, and refractive surgery. Although contact lenses do provide wearers with more freedom to perform sports and certain professional activities than glasses, they also involve strict daily hygiene in order to avoid any damage to the eye. Not to mention the fact that certain individuals do not tolerate contact lenses very well.
Of all these options, only one can banish all of the constraints associated with wearing and looking after glasses or contact lenses: refractive surgery.
This rapid and painless procedure can be performed on anyone above the age of 20 whose vision has remained stable for at least 2 years.
A thorough preliminary examination is carried out first in order to determine which procedure is best suited to the patient, in particular depending on the shape of their cornea.
Your questions about astigmatism
Is there surgery available to correct astigmatism?
Yes. Astigmatism correction is commonplace in refractive surgery, as this defect is sometimes isolated but is more often associated with myopia or hyperopia. Contrary to popular belief, astigmatism is operable whether isolated or associated with another optical defect.
Is astigmatism hereditary?
Astigmatism is usually genetic. This means that it is present from birth and remains relatively stable over a person’s lifetime. It is also possible to develop astigmatism later in life, for example following a surgical procedure (cataract surgery, corneal graft) or as a result of an infection, herpes virus or certain other diseases.
Is astigmatism progressive?
No. In the absence of other pathologies, astigmatism does not generally progress over time, unlike myopia and hyperopia. That is why it is important to consult an ophthalmologist in order to rule out the possibility of keratoconus when children or young adults experience a sudden deterioration in their astigmatism.
Myopia is the most common refractive issue. It is caused by the eye being too long and/or the cornea being too curved. It results in distance vision becoming blurry.
Hyperopia is caused by the eye being too short and/or the cornea being too flat. This means additional focussing power is required in order to see clearly, which is referred to as accommodation. People with hyperopia have better distance vision than near vision.
Presbyopia is a common visual defect in individuals aged over 40. This vision problem becomes evident as the eye ages. It results in a progressive deterioration of near vision with age.