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Understanding Astigmatism

About Astigmatism

Astigmatism refers to a general blurriness of vision that often accompanies nearsightedness (myopia) and farsightedness (hyperopia). It happens when light passes through the eye does not focus on a single point on the retina, the light-sensitive tissue located at the back of the eye. This tends to be caused by asymmetry of the cornea or lens of the eye.

You may have heard it referred to as "stigmatism." This is a common misnomer.

Types of Astigmatism

There are actually two different kinds of astigmatism, and it's important that our laser eye surgeons correctly identify what kind of astigmatism a person is suffering from in order for the proper treatment to be performed. These two kinds of astigmatism are:

  • Corneal astigmatism - This is astigmatism that is related to irregular shape of the cornea
  • Lenticular astigmatism - This is astigmatism that is related to irregular shape of the lens of the eye


Astigmatism can be further divided into these categories

  • Myopic astigmatism - One or both meridians of the the eye are myopic.
  • Hyperopic astigmatism - One or both meridians of the the eye are hyperopic.
  • Mixed astigmatism - One meridian of the eye is myopic while the other is hyperopic


In addition, there is both regular astigmatism and irregular astigmatism. They can be defined thusly:

  • Regular astigmatism - The meridians of the eyes are perpendicular, resulting in a football shape
  • Irregular astigmatism - A rarer form of astigmatism in which the meridians are not perpendicular; it's often caused by eye injury or kerataconus, a condition in which the cornea becomes misshapen

Treating Corneal Astigmatism

When it comes to treating corneal astigmatism, the best options for care tend to be LASIK, other refractive surgery options, and corrective lenses. The right treatment for a patient will vary based on the patient's individual situation.

Treating Lenicular Astigmatism

When it comes to treating lentiular astigmatism, the best options for care tend to be an implantable contact lens (ICL), an intraocular lens (IOL), or corrective lenses. As with corneal astigmatism, the right treatment for a patient will vary based on the patient's individual situation.

Treating Irregular Astigmatism

Irregular astigmatism presents a number of challenges for treatment. If the irregular astigmatism is the result of kerataconus, the best options tend to be the use of special corrective lenses and contact lenses. In some cases, a corneal transplant or other surgical treatment may be required.

For eye injuries, the treatment will vary, though often the correction of the eye injury comes first to ensure ocular health followed by the use of corrective lenses. Circumstances will vary, which is why it's important for these matters to be discussed during a consultation.

Learn More About Advanced Eye Care Treatments

For more information about treatments for astigmatism and your many other options for advanced treatment of the eyes, be sure to contact our Toronto eye care and laser vision correction center today. The entire team here looks forward to meeting you in person and helping you achieve the best possible eyesight.