What is Keratoconus?

Normal Cornea vs. Keratoconic Cornea Vision Simulator

Keratoconus, often referred to as ‘KC’, is an eye condition in which the cornea weakens and thins over time, causing the development of a cone-like bulge and optical irregularity of the cornea. Keratoconus can result in significant visual loss and may lead to corneal transplant in severe cases.

Drag slider in either direction to simulate a keratoconus patient’s vision.

Simulation of Keratoconus Patient VisionCreative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. Changes have been made to the original image. Times Square image by Spreng Ben (CC BY-NC-SA 2.0)

Top Questions to Ask Your Eye Doctor

Who’s Affected by Keratoconus?

Keratoconus Affects Both Genders although it is unclear

whether significant differences exist between males and females

The Disease is Also Found in All Ethnic Groups with some studies

showing higher incidence rates among Asian populations, in particular

Explore Our Keratoconus Infographic


A rare condition, keratoconus typically first appears in individuals who are in their late teens or early twenties, and may progress for 10-20 years, and then slow or stabilize. Each eye may be affected differently. In the early stages of keratoconus, people might experience:

Slight Blurring of Vision

Distortion of Vision

Increased Sensitivity to Light

Treatment Options

Treatment options for keratoconus focus on correcting the distorted vision caused by the thinning and bulging of the cornea.

Vision Rehabilitation

Eyeglasses or Soft Contact Lenses

Mild and early cases of keratoconus can be managed with glasses or traditional non-specialty soft contact lenses if the degree of corneal distortion is not too severe. Typically, in these cases, soft astigmatism correcting contact lenses are required. More advanced cases can be treated with specialty soft lenses, designed specifically for keratoconus. These lenses typically have a thick central optic zone to mask the corneal irregularity and a thin periphery for comfort. Cases of moderate and somewhat severe keratoconus can be treated with these specialty lenses. These lenses are limited in terms of whether they can provide adequate vision correction for the individual, especially as the condition progresses.

Rigid Gas Permeable Contact Lenses

Rigid Gas Permeable (RGP) contact lenses are rigid lenses made of durable plastic that can transmit oxygen; Scleral contacts are also gas permeable, but are larger diameter, designed to cover the entire cornea plus a portion of the white of the eye; Hybrid contacts are RGPs surrounded by a soft lens lining or skirt.


Intacs is the trademark name for micro-thin prescription corneal implants designed for the reduction or elimination of myopia and astigmatism in patients with keratoconus. Intacs are thin plastic, semi-circular rings, which are surgically inserted under the surface of the cornea. When inserted into the keratoconic cornea, they flatten the cornea, changing its shape. The placement of Intacs may reduce corneal irregularities caused by keratoconus.

Intervention – To Halt or Slow Disease Progression

FDA-Approved Corneal Cross-Linking (iLink®)

Corneal cross-linking is a minimally invasive outpatient procedure that combines the use of ultra-violet (UV) light and riboflavin (vitamin B2) eye drops. Photrexa® Viscous (riboflavin 5’-phosphate in 20% dextran ophthalmic solution), Photrexa® (riboflavin 5’-phosphate ophthalmic solution) and the KXL® system are the first and only therapeutic products for corneal cross-linking which have been FDA approved to treat progressive keratoconus.

For more information go to: What is Cross-Linking?

End-Stage Surgery

Corneal Transplant Surgery

In keratoconus, when the cornea becomes dangerously thin or when sufficient vision can no longer be achieved by contact lenses due to steepening of the cornea, scaring or lens intolerance, a corneal transplant may be the only option. The surgery is generally performed as an outpatient procedure with either general or local anesthesia. During the surgery, the part of the cornea affected by keratoconus is removed and replaced with a donor cornea. While the surgical transplantation of a new cornea will resolve the basic problem of corneal surface irregularity, eyeglasses or contact lenses are usually needed after the surgery for vision correction.

Looking for a Cross-Linking Expert?


Learn more about this rare eye condition

View our Living with Keratoconus Patient Brochure.


Learn more about this minimally invasive procedure

Visit the Cross-Linking Section to learn more.

Corneal cross-linking provides patients a much-needed option to treat this debilitating disease. Patients suffering from progressive keratoconus can now receive a therapeutic treatment that has been rigorously tested and approved.”

Mary Prudden, Executive Director for the National Keratoconus Foundation

Impact Over Lifetime

Early diagnosis and treatment allowed Richard and Jessa to be able to continue to enjoy their active lifestyles.

A KC diagnosis put Richard’s firefighting career in danger. Cross-linking helped save it.

Jessa chose cross-linking to manage her progressive KC. Now, she can focus on being a teenager.

What are Patients Saying?