News and Advice on Myopia and General Eye Care for Patients and Professionals

What is Astigmatism?

Paragon Vision February 13, 2020 Nearsighted, CRT Lenses, Contact Lenses, Orthokeratology, FDA Approved, Myopia, Ortho-K, optometrist, Eye Doctor, corneal refractive therapy, CRT, vision, what is myopia, nearsightedness, eye health, vision health, eyes, health, paragon vision sciences, astigmatism, dual axis, Paragon CRT Dual Axis®


Struggle to see clearly at a distance? You may be nearsighted. You may also have astigmatism, a refractive condition in which light does not focus equally on the retina, the light-sensitive surface at the back of the eye. As a result, vision may appear blurred, smeared, or distorted at any distance. Astigmatism frequently occurs with other vision conditions like nearsightedness and farsightedness but can be present by itself.1 The diagram below shows the difference between a non-astigmatic eye and astigmatic eye.


Figure 1 shows how an astigmatic cornea is not spherical, preventing light from focusing equally on the retina . A normal cornea is round, like a basketball.  In the diagram the surface of the astigmatic cornea is shaped more like a football instead of the typical round, basketball shape. If the cornea is not spherical, the eye is unable to focus light rays to a single point and vision becomes out of focus.

What’s the Cause?

Astigmatism is mostly caused by genetics and can increase or decrease over time. Astigmatism can be connected to any prescription of myopia (nearsightedness) or prescription of hyperopia (farsightedness).

From blurry to distorted vision, astigmatism can be a real hindrance to your quality of life. When frequently paired with a condition such as nearsightedness, it goes beyond an inconvenience and becomes a matter of eye health. When nearsightedness is left untreated, future risks of retinal detachment, glaucoma, macular degeneration, and blindness are increased.2 It is imperative that parents stay on top of a child’s eye health. The American Optometric Association recommends that children have eye exams when they are 6 months old and 3 years old. After that, children should receive routine exams every 2 years, or more frequently, from ages 6 to 18.3 Even adults need to be aware of the rising epidemic of nearsightedness and that there are many options to treat the condition. In the United States, the incidence of nearsightedness has increased by 66% since 1971.4 By 2050, half of the world’s population could be nearsighted!5

What Are My Treatment Options?

Your everyday soft spherical contact lens isn’t going to always fit on a cornea that is astigmatic. Because the cornea is shaped differently, many with this condition need to wear a special toric lens instead of a standard contact lens. Eyeglasses that contain a cylindrical lens prescription may be an effective treatment option. The cornea can also be reshaped by surgery.

Then there is a treatment option called orthokeratology (Ortho-K). This is the use of rigid contact lenses that correct a cornea’s myopic and astigmatic prescription. Paragon CRT Dual Axis® is a special contact lens that is made specifically for nearsighted astigmatic patients. This contact lens treats nearsightedness and astigmatism while you sleep! Worn overnight, the lenses gently reshape the curvature of the cornea. In the morning you remove the lenses for clear vision without the need for glasses or daytime contacts. Imagine the FREEDOM you can have. Paragon CRT Dual Axis® is the go-to lens for many of the world’s top contact lens fitters!6 With Paragon CRT Dual Axis® you will have peace of mind knowing you are wearing a medical device that is FDA approved and has a satisfaction rating of 97.6%.7,8

How Do I Get Started with Overnight Contacts?

Let go of worrying about breaking your glasses while camping. Forget the anxiety of possibly losing a contact lens while whitewater rafting. Say goodbye to the concern that your child will jump in the pool with their soft contact lenses on. With overnight contacts there is no risk of your child forgetting their glasses at home or at school.

Only a Paragon CRT® certified eye doctor can prescribe these lenses. Whether astigmatic or not, you deserve freedom from glasses and daytime contacts. If you are not eligible for surgery, Paragon CRT Dual Axis® can be a great alternative. Find a doctor near you by using our doctor locator tool.

Your vision health is important. With nearsightedness being the most common vision issue, we know parents and patients want choices when it comes to their treatment. Ortho-K lenses offer you an innovative and noninvasive way to treat your nearsightedness – all in a good night’s sleep.


[1] Astigmatism. (n.d.). Retrieved January 30, 2020, from

[2]  Xu L, Wang Y, Wang S, Wang Y & Jonas JB, ‘High Myopia and Glaucoma Susceptibility: The Beijing Eye Study’ Ophthalmology, Volume 114, Issue 2, February 2007; Praveen MR,Shah 5, GD, Vasavada AR, Mehta PG, Gilbert C & Bhagat G ‘A study to explore the risk factors for the early onset of cataract in India’, Eye, 24,

[3] Recommended Eye Examination Frequency for Pediatric Patients and Adults. (n.d.). Retrieved January 30, 2020, from

[4] Vitale S, Sperduto RD, Ferris FL 3rd. Increased Prevalence of Myopia in the U.S. between 1971-1972 and 1999-2004. Arch Ophthalmol. 2009 Dec;127(12):1632-9. PubMed

[5] Holden, B. A., T. R. Fricke, D. A. Wilson, M. Jong, K. S. Naidoo, P.
Sankaridurg, T. Y. Wong, T. J. Naduvilath and S. Resnikoff (2016).
"Global Prevalence of Myopia and High Myopia and Temporal Trends from
2000 through 2050." Ophthalmology 123(5): 1036-1042.

[6] Paragon Vision Sciences, Data on File

[7] FDA Approval Letter

[8] Paragon Vision Sciences, Consumer Survey, Data on File, July 2019