Keratoconus usually begins quietly, often in the teens or twenties, and its early signs are easy to mistake for an ordinary need for stronger glasses. Catching it early matters more than most people realize, because the progression can often be slowed or halted when it’s found in time. Here are the signs worth paying attention to.
What is keratoconus?
Keratoconus is a condition in which the normally round cornea — the clear front window of the eye — gradually thins and bulges into an irregular, cone-like shape. That distortion scatters light and blurs vision in a way ordinary glasses can’t fully fix. You can learn more about how we diagnose and manage it on our keratoconus page.
Early signs and symptoms
Prescription that keeps changing
One of the earliest clues is a glasses or contact prescription that changes noticeably every few months, especially a rapid increase in astigmatism. If your eye doctor keeps adjusting your prescription and it never quite “sticks,” it’s worth asking about keratoconus.
Blurry or distorted vision
Straight lines may look slightly wavy or bent, and vision can seem smeared even with the latest prescription. This distortion comes from the irregular corneal surface.
Glare and halos at night
Increased glare around lights, starbursts, and halos — particularly when driving at night — are common early complaints.
Light sensitivity and eye strain
Many people notice growing sensitivity to bright light along with eye strain and headaches from constantly straining to focus.
Ghosting and double vision in one eye
Seeing a faint second image or “ghost” — even with the other eye closed — is a classic keratoconus symptom that ordinary refractive errors don’t usually cause.
Itchy eyes and frequent rubbing
Chronic eye rubbing, often tied to allergies, is strongly associated with keratoconus. We explore this in keratoconus and eye rubbing.
Who is most at risk?
Keratoconus most often appears in adolescence and early adulthood. Risk is higher with a family history of the condition (more in is keratoconus genetic?), frequent eye rubbing, chronic allergies or eye irritation, and certain conditions such as Down syndrome and connective-tissue disorders.
Why early detection matters so much
Here’s the key point: a procedure called corneal cross-linking can often halt progression when keratoconus is caught early, preserving the vision you still have. Waiting until vision is badly affected limits your options. Learn how progression can be slowed in can you stop keratoconus from getting worse? and about the procedure itself in corneal cross-linking.
How keratoconus is diagnosed
A standard vision test isn’t enough. Diagnosis relies on corneal topography or tomography, which maps the precise shape and thickness of the cornea and can detect keratoconus before you’d notice major symptoms. From there, your doctor stages the condition and builds a plan — see the stages of keratoconus.
The takeaway
If your vision is changing quickly, distorting, or worsening at night, don’t simply assume you need stronger glasses. A focused keratoconus evaluation can rule it out — or catch it early enough to protect your sight.
Noticing these signs in your vision?
Dr. Shira Kresch is a keratoconus and specialty lens specialist at Michigan Contact Lens in Southfield, serving patients across Metro Detroit. Your initial consultation is complimentary.
