Keratoconus (ker-uh-toe-KOH-nus) occurs when your cornea — the clear, dome-shaped front surface of your eye — thins and gradually bulges outward into a cone shape.

A cone-shaped cornea causes blurred vision and may cause sensitivity to light and glare. Keratoconus usually affects both eyes and generally begins to first affect people ages 10 to 25. The condition may progress slowly for 10 years or longer.

In the early stages of keratoconus, you can correct vision problems with glasses or soft contact lenses. Later you may have to be fitted with rigid gas permeable contact lenses or other types of lenses. If your condition progresses to an advanced stage, you may need a cornea transplant.

Keratoconus care at Mayo Clinic

Jan. 30, 2016
  1. Wayman LL. Keratoconus. http://www.uptodate.com/home. Accessed Nov. 24, 2015.
  2. What is keratoconus? American Academy of Ophthalmology. http://www.geteyesmart.org/eyesmart/diseases/keratoconus.cfm. Accessed Nov. 24, 2015.
  3. Keratoconus treatment. American Academy of Ophthalmology. http://www.geteyesmart.org/eyesmart/diseases/keratoconus-treatment.cfm. Accessed Nov. 24, 2015.
  4. van der Worp E, et al. Modern scleral contact lenses: A review. Contact Lens & Anterior Eye. 2014;37:240.
  5. Raiskup F, et al. Corneal collagen crosslinking with riboflavin and ultraviolet-A light in progressive keratoconus: Ten-year results. Journal of Cataract and Refractive Surgery. 2015;41:41.
  6. Jinabhai A, et al. Optical quality and visual performance with customised soft contact lenses for keratoconus. Opthalmic and Physiological Optics. 2014;34:528.
  7. Amayem AF, et al. Refractive and visual outcomes of penetrating keratoplasty versus deep anterior lamellar keratoplasty with hydrodissection for treatment of keratoconus. Cornea. 2013;32:e2.
  8. Keratoconus diagnosis. American Academy of Ophthalmology. http://www.geteyesmart.org/eyesmart/diseases/keratoconus-diagnosis.cfm. Accessed Nov. 24, 2015.
  9. Riggin EA. Allscripts EPSi. Mayo Clinic, Rochester, Minn. July 27, 2015.
  10. Keratoconus. American Optometric Association. http://www.aoa.org/patients-and-public/eye-and-vision-problems/glossary-of-eye-and-vision-conditions/keratoconus?sso=y. Accessed Dec. 23, 2015.
  11. Keratoconus. Merck Professional Version. http://www.merckmanuals.com/professional/eye-disorders/corneal-disorders/keratoconus. Accessed Dec. 23, 2015.
  12. Yanoff M, ed., et al. Testing of refraction. In: Ophthalmology. 4th ed. Edinburgh, U.K.: Mosby Elsevier; 2014. https://www.clinicalkey.com. Accessed Oct. 30, 2014.
  13. Yanoff M, ed., et al. Keratoconus and other ectasias. In: Ophthalmology. 4th ed. Edinburgh, U.K.: Mosby Elsevier; 2014. https://www.clinicalkey.com. Accessed Oct. 30, 2014.
  14. Patel SV (expert opinion). Mayo Clinic, Rochester, Minn. Jan. 5, 2016.