Can You Have Keratoconus in One Eye?

Can You Have Keratoconus in One Eye?

by Brian Chou, OD, FAAO, FSLS

January 21, 2024


The short answer is that keratoconus naturally affects both eyes. But this is a trick question. There are unusual and unexpected instances of keratoconus in just one eye! Read on to learn how.

Keratoconus Affects Both Eyes

As a genetic eye disease, keratoconus affects both eyes although often asymmetrically. Sometimes the asymmetry is so pronounced that one eye may seem normal. In the past, diagnostic technologies were not sensitive enough to detect subtle indicators of keratoconus. Consequently, some patients seemed to have keratoconus in just one eye. But as diagnostic technology has improved with better sensitivity, many of these former cases of keratoconus supposedly in just one eye are now known as cases affecting both eyes.

Today, keratoconus is understood as bilateral, that is, affecting both eyes. Even so, it is actually possible to have keratoconus in one eye.

The Two Unusual Situations Where Keratoconus Is Present in One Eye

The first way is if one eye is taken out, or enucleated, due to disease or catastrophic trauma. This is obviously rare, and fortunately so.

The second way of having keratoconus in one eye is when the distorted cornea in one eye is replaced with a full-thickness corneal transplant. Historically, about 20% with keratoconus would need a full-thickness corneal transplant. However, the success of scleral contact lenses has reduced the number of corneal transplants for keratoconus by about 80%. The plot twist is that there are isolated reports of keratoconus recurring in the corneal graft after full-thickness corneal transplantation.

If you have keratoconus and believe you have the condition in only one eye, more likely than not, you’ll want to think again.


ReVision Optometry is a referral-based practice in San Diego providing contact lens services for patients with keratoconus and other complex eye conditions. To schedule an appointment, request your examination online or call our office at 619.299.6064.