Astigmatism is a common eye condition or refractive error diagnosed with the help of an eye exam. It can also occur with other refractive errors like nearsightedness and farsightedness.
Astigmatism can lead to blurred vision, headaches, and eye strain. While it can be managed with corrective lenses, specialty contact lenses, or surgery, astigmatism can gradually worsen due to age, eye injuries, or other eye conditions.
What Is Astigmatism?
Astigmatism is a common vision problem that can affect children and adults. Astigmatism occurs when the cornea (the clear front part of the eye) or lens (the inner part of the eye used to focus light) has an irregular shape, typically more oblong than round.
The irregular—or football—shape causes light entering the eye to refract unevenly rather than focusing on the retina, the light-sensitive tissue at the back of the eye. When that happens, your vision can become blurry at every distance.
In addition to blurry vision, the signs and symptoms of astigmatism can include:
- Eye strain or discomfort
- Headaches
- Squinting
Astigmatism can affect anyone, but your family history can play a significant role in the development and worsening of astigmatism. Children with parents who have astigmatism are more likely to experience the same challenges.
Most people with astigmatism are born with it. However, it can develop later for the following reasons:
- Due to an eye injury
- As a complication of other eye conditions, such as keratoconus
- As a complication of eye surgery
- Due to other changes in the shape of the cornea
Types of Astigmatism
Astigmatism can be classified as regular or irregular. Regular astigmatism occurs when the cornea or lens of the eye is misshapen in an even way, while irregular astigmatism occurs with an uneven misshapen curve in the eye.
There are also 3 other types of astigmatism:
- Myopic astigmatism: astigmatism combined with nearsightedness.
- Hyperopic astigmatism: astigmatism combined with farsightedness.
- Mixed astigmatism: astigmatism that occurs when one curve is myopic (nearsighted) and the other is hyperopic (farsighted).
Factors that Can Worsen Astigmatism
Astigmatism, like other refractive errors, can be corrected with glasses, contact lenses, and laser eye surgery. However, it can worsen over time due to changes in eye shape and other factors.
Age-Related Changes in the Eye
Some children with astigmatism outgrow it. However, after about age 25, astigmatism that still affects a person’s vision will usually remain.
Astigmatism can also become more pronounced with age, often in conjunction with the development of other eye conditions. For these reasons, regular eye exams are essential for monitoring your eye health and vision when you have astigmatism.
Eye Injuries or Trauma
Serious injuries to the eye can alter its shape or cause scarring and, in turn, affect how light enters and refracts in the eye. Preventive measures, such as wearing protective eyewear during sports and other physical activities, can help prevent eye injuries.
Eye Surgery
Some surgical procedures, such as cataract surgery, may cause astigmatism as a side effect. Cataract surgery can also worsen mild astigmatism because it involves an incision through the cornea, which can change its curvature.
Eye Conditions
Certain eye conditions, such as keratoconus, can contribute to and sometimes even worsen astigmatism. Keratoconus affects the cornea and causes it to thin and bulge out. It’s a progressive eye disease that can lead to vision impairment and often can’t be corrected fully with glasses.
Treatment for Astigmatism
The treatment options for astigmatism depend on the severity of the condition and your specific needs. Corrective lenses may not be able to correct some types of astigmatism, in which case surgery may be recommended.
Eyeglasses
Eyeglasses are one of the most common and simplest ways to treat astigmatism. Prescription glasses lenses can compensate for the irregular shape of the cornea or lens to provide clearer vision.
Contact Lenses
Some contact lenses, including rigid gas-permeable (RGP) lenses, can also correct astigmatism. Specialty contact lenses, such as scleral lenses, can be especially beneficial for people with astigmatism.
Scleral contact lenses are specifically designed to vault over the cornea and rest on the whites of the eye. These lenses can provide clear vision with a fluid reservoir that helps compensate for irregularities in the cornea’s curvature by creating a smooth, even surface for light to pass through.
Orthokeratology
Orthokeratology involves wearing specially designed rigid contact lenses overnight to reshape the cornea temporarily. The temporary reshaping allows for clearer vision during the day without corrective lenses and can help some people with astigmatism see clearly.
Refractive Surgery
Laser eye surgery can correct astigmatism by reshaping the cornea. This surgical option is generally considered for individuals with moderate to severe astigmatism who want to reduce their dependence on glasses or contact lenses.
It’s important to consult your eye doctor if you have astigmatism to determine the most appropriate treatment option based on your personal eye health, lifestyle, and preferences. Regular eye exams are also essential for monitoring astigmatism and determining whether corrective measures remain effective over time.
Preserve Your Sight
While you typically can’t prevent astigmatism caused by genetics or age, you can take a proactive approach by having regular eye exams, protecting your eyes from injury, and managing your astigmatism effectively.
Early detection and intervention are key to preventing worsening astigmatism and preserving your sight. For changes in your vision or worsening vision symptoms, book an appointment with Toronto Centre Eye Care.
