What is Keratoconus?

Keratoconus is a progressive disease affecting the front window of the eye and the cornea. It results in poor vision that cannot be corrected fully with glasses. Keratoconus usually begins in the late teenage years. However, it can start in the 20s or early 30s. Keratoconus causes the cornea at the front of the eye to become thin and bow outwards. It is this irregular distortion of the cornea that makes vision correction with glasses less effective. For this reason, other means of correcting vision are often necessary.

What causes keratoconus? 

There is no known cause of keratoconus but it can be hereditary. It has also been linked to chronic eye rubbing as well as Down Syndrome.

Does keratoconus result in blindness?

Keratoconus does not result in complete blindness, although it can cause very blurred and distorted vision. Improving the vision of someone with keratoconus requires patience and persistence on the part of the patient and optometrist. This is because no single treatment option works on every patient and the condition can change frequently and rapidly.

How do you correct keratoconus? 

Glasses and/or soft contact lenses may be used to successfully correct mild keratoconus. More moderate keratoconus is best corrected with rigid gas permeable contact lenses, which provide a smooth tear layer in front of the cornea, making clear vision possible. Since the lens is rigid, the tears between the lens and the cornea form a “liquid lens” which smooth the irregularities of the cornea and make clear vision possible again.

Is surgery for keratoconus necessary? 

As keratoconus progresses, surgery may be considered, especially if the cornea is becoming thin or scarred.


“Keratoconus”, Ontario Association of Optometrists, Retrieved 18 July 2019. <https://www.optom.on.ca/OAO/Patients/Library/Keratoconus.aspx>