Keratoconus often affects both eyes, and can lead to very different vision between the two eyes. Symptoms can differ in each eye, and they can change over time.
In the early stage, keratoconus symptoms can include:
- mild blurring of vision
- slightly distorted vision, where straight lines look bent or wavy
- increased sensitivity to light and glare
- eye redness or swelling
Left: normal cornea; right: cornea with keratoconus.
In later stages, keratoconus symptoms often include:
- more blurry and distorted vision
- increased nearsightedness or astigmatism (when your eye cannot focus as well as it should). As a result, you may need new eyeglass prescriptions often.
- not being able to wear contact lenses. They may no longer fit properly and they are uncomfortable.
Keratoconus usually takes years to go from early to late stage. For some people, though, keratoconus can get worse quickly. The cornea can swell suddenly and start to scar. When the cornea has scar tissue, it loses its smoothness and becomes less clear. As a result, vision grows even more distorted and blurry.