Complications

In some situations, your cornea may swell quickly and cause sudden reduced vision and scarring of the cornea. This is caused by a condition in which the inside lining of your cornea breaks down, allowing fluid to enter the cornea (hydrops). The swelling usually subsides by itself, but a scar may form that affects your vision.

Advanced keratoconus also may cause your cornea to become scarred, particularly where the cone is most prominent. A scarred cornea causes worsening vision problems and may require cornea transplant surgery.