Astigmatism - Symptoms, Tests, Causes, Treatment and Diagnosis

Creator: Dr. Nandini Sankaranarayanan
Published: 2025-01-30 21:36:20

Written By: Dr. Nandini Sankaranarayanan

Updated On:January 30, 2025

What is Astigmatism?

Astigmatism is the result of misaligned curves in either the internal lens or the cornea, the front surface of the eye. Astigmatism results in blurry vision and can coexist with near-sightedness or farsightedness and is frequently present from birth. Frequently, it's not severe enough to call for intervention. If so, surgery or corrective lenses are available as treatments.

Causes of Astigmatism

Astigmatism occurs when the cornea or lens is bent more sharply in one direction than another. If the curves in your cornea are not aligned, you have corneal astigmatism. If you have uneven curves in your lens, you have lenticular astigmatism. Visibility problems might arise from any kind of astigmatism.

Astigmatism can occur following an eye injury, illness, or surgery, or it might be present from birth. Squinting, reading in dim light, or sitting too close to the TV do not induce or exacerbate astigmatism.

Symptoms of Astigmatism

Astigmatism signs and symptoms might include:

blurred eyesight
eyestrain
headaches
challenges with night vision
squinting.

When to see a doctor for Astigmatism?

If your eye symptoms make it difficult for you to carry out daily duties, you should see an eye doctor. Your doctor can determine if and to what extent you have astigmatism. After that, your doctor can counsel you on vision correction alternatives.

Astigmatism Risk Factors

Both adults and children can develop astigmatism. If you have any of the following, you may be more likely to acquire astigmatism:

a history of astigmatism in your family or other eye conditions, such as keratoconus (corneal degeneration),
corneal scarring or thinning,
excessive nearsightedness (which causes fuzzy vision up close),
excessive farsightedness (which causes blurry vision up close),
or a past medical history of certain eye procedures, such as cataract surgery (removal of a clouded lens by surgery).

Astigmatism Complications

Astigmatism can lead to complications if neglected. For instance, if astigmatism in one eye is untreated or if astigmatism in one eye is more severe than the other, the result may be a lazy eye, also known as amblyopia. Furthermore, astigmatism can occasionally result in headaches and eye strain.

There are complications associated with astigmatism surgery, too. Surgery frequently has transient side effects that go away in a few weeks. These include issues with night vision, light sensitivity, and dry eyes. However, there may also be additional (and more serious) side effects, such as eyesight loss or a return of pre-surgery vision.

Astigmatism Diagnosis

An eye exam is used to identify astigmatism. A refraction, which measures how the eyes bend light, and a battery of tests to assess eye health are both included in a comprehensive eye exam. Your eye doctor may ask you to look through many lenses, use a variety of devices, and shine strong lights straight into your eyes. These tests are used by your doctor to assess several facets of your eyes and eyesight and to calculate the prescription required for glasses or contact lenses that will give you clear vision.

Astigmatism Treatment

By correcting the uneven curvatures of your cornea or lens, corrective lenses can address astigmatism.

Corrective lenses come in several forms, such as contact lenses and eyeglasses, which help balance out the uneven eye shape.
Refractive surgery lessens the need for contact lenses or glasses while improving eyesight. The refractive defect is corrected by an eye surgeon reshaping the cornea with a laser beam. Doctors will assess you to see if you are a good candidate for refractive surgery before surgery. Types of refractive surgery for astigmatism include:
- Laser-assisted in-situ keratomileusis (LASIK): During this process, a corneal flap that is hinged and thin is created by the eye surgeon. The doctor repositions the flap after shaping the cornea's shape with an excimer laser.
- Laser-assisted subepithelial keratectomy (LASEK): The cornea's thin protective layer, known as the epithelium, is loosened by the surgeon using a unique alcohol rather than making a flap in the cornea. After modifying the cornea's curvature with an excimer laser, he or she repositions the loosened epithelium.
- Photorefractive keratectomy (PRK): Except for epithelium removal, this surgery is comparable to laser-assisted subepithelial keratectomy (LASEK). Naturally, it will regrow and take on the new shape of the cornea. A bandage contact lens may be required for a few days following surgery.
- Epi-laser-assisted in situ keratomileusis (LASIK): The surgeon separates a very thin strip of epithelium using a specific motorized blunt blade in place of alcohol. The cornea is then reshaped and the epithelium is repositioned using an excimer laser.
- Small-incision lenticule extraction (SMILE): This more recent kind of refractive surgery modifies the cornea by creating a lens-shaped lentula (a piece of tissue beneath the surface of the cornea) using a laser. A little incision is then made to remove the lenticule. Currently, mild nearsightedness is the only condition for which the minor incision lenticule extraction (SMILE) technique is allowed.

Astigmatism Prevention

Astigmatism cannot be prevented. While many people develop astigmatism as children or early adults, other people have it from birth. Astigmatism can also occur in certain persons following eye surgery or an accident. As soon as you exhibit any of the symptoms, make sure to consult with your healthcare provider as not to develop any of the associated consequences.

References

Keshav, V., & Henderson, B. A. (2021). Astigmatism management with intraocular lens surgery. Ophthalmology, 128(11), e153-e163.

Namba, H., Sugano, A., Murakami, T., Utsunomiya, H., Nishitsuka, K., Ishizawa, K., ... & Yamashita, H. (2020). Age-related changes in astigmatism and potential causes. Cornea, 39, S34-S38.

Reinstein, D. Z., Archer, T. J., Vida, R. S., Carp, G. I., Reinstein, J. F., & McAlinden, C. (2022). Objective and subjective quality of Vision after SMILE for high myopia and astigmatism. Journal of Refractive Surgery, 38(7), 404-413.

Yeu, E. (2020, May). Astigmatism Management. In 2020 ASCRS Annual Meeting. ASCRS.

Zhang, J., Wu, Y., Sharma, B., Gupta, R., Jawla, S., & Bullimore, M. A. (2023). Epidemiology and burden of astigmatism: a systematic literature review. Optometry and Vision Science, 100(3), 218.