Keratoconus Symptoms & Diagnosis

The earliest signs of keratoconus are usually blurred vision and  frequent changes in eye glass prescription, or  vision that cannot be corrected with glasses. Symptoms of keratoconus generally begin in late teenage years or early twenties, but can start at any time.

Images courtesy of Ian McCain and Elio Spinello,

Other symptoms include:

  • Increased light sensitivity

  • Difficultly driving at night

  • A halo around lights and ghosting (especially at night)

  • Eye strain

  • Headaches and general eye pain

  • Eye irritation, excessive eye rubbing

Keratoconus, especially in the early stages can be difficult to diagnose and all of the above symptoms could be associated with other eye problems. Simply recognizing symptoms does not by itself diagnose keratoconus.

Keratoconus requires a diagnosis from a competent eye doctor trained not only in recognizing the symptoms but also observing signs of keratoconus through direct measurement as well as inspection of the cornea at a microscopic level using a slit lamp.

Always consult your doctor to confirm a diagnosis of Keratoconus.

Keratoconus Diagnosis & Treatment

Keratoconus can usually be diagnosed with a slit-lamp examination.  The classic signs of keratoconus that the doctor will see when examining your eyes include:

  • Corneal thinning

  • Fleischer’s ring (an iron colored ring surrounding the cone)

  • Vogt’s striae (stress lines caused by corneal thinning)

  • Apical scarring (scarring at the apex of the cone)

The doctor will also measure the curvature of the cornea. This is done by:

  • Keratometry:  an instrument that shines a pattern of light onto the cornea. The shape of the reflection of the pattern tells the doctor how the eye is curved.

  • Corneal topography: a computerized instrument that make three-dimensional “maps” of the cornea

A typical corneal topography map looks like this:


Corneal topography has facilitated the diagnosis of keratoconus, helping establish the diagnosis earlier, follow progression more accurately and differentiate keratoconus from other conditions.

Video courtesy of Dr. Michael Hodkin