Corneal Refractive Therapy, or CRT® lenses, are a non-surgical option that helps correct nearsightedness without the daytime use of contacts or glasses. CRT lenses are worn at night, and correct the curvature of the cornea while sleeping so you can see clearly during the day.

How Do CRT Lenses Work?

The Science Behind CRT Lenses

Ortho-K (short for Orthokeratology) is a non-surgical solution for patients with myopia (nearsightedness) that uses specially designed contact lenses (like Paragon CRT® lenses) to improve vision.

When worn overnight, Paragon CRT® contact lenses gently corrects the curvature of the cornea, resulting in a corneal shape that focuses light correctly onto the retina. When removed in the morning, distant objects will come back into focus and patients can see clearly without the use of glasses or daytime contacts.

Learn About Myopia

Paragon CRT® Contact Lenses First FDA approval for overnight use

Our goal is to correct your vision by eliminating daytime use of eyeglasses or contact lenses. In the FDA trials for Paragon CRT® contact lenses, more than 90% were able to see 20/40 or better1 (the legal vision requirement for driving without glasses in most states).
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They are the perfect solution for patients who:

  • Want a lens-free lifestyle during the day
  • Find soft contacts too irritating
  • Are too young for LASIK or are not a LASIK candidate

Paragon CRT has been prescribed to over 1.5 million patients, in over 50 countries worldwide.2 The risk of wearing Paragon CRT contact lenses is no greater than other contact lenses.4

Myopia Assessment

Could CRT Be Right for Me or My Child?

Myopia (nearsightedness) usually begins in childhood, as early as age 6. When left uncorrected, myopia can affect a child’s ability to learn and develop.5

If you or your child suffers from any of the following symptoms of myopia, Paragon CRT® contact lenses might be right for you:

  • Blurred vision when viewing distant objects
  • Frequent squinting and blinking
  • Headaches
  • Difficulty with nighttime driving
  • Needing to sit closer to the television or computer
  • Holding books and tablets uncomfortably close while reading
  • Falling behind in school