The cornea is the transparent dome-shaped window in the front of the eye. Focus the light in the eye. Keratoconus is when the cornea becomes thin and sticks out like a cone. Changing the shape of the cornea causes the light rays to blur. As a result, vision is blurred and distorted, which makes daily tasks like reading and driving difficult.

Doctors don't know for sure why people can have keratoconus. In some cases, it seems to be genetic (runs in the family). Approximately 1 in 10 people with keratoconus has a relative who also has it. Keratoconus is also associated with eye allergies and excessive rubbing of the eyes.

Keratoconus usually appears in people during their late adolescence until the beginning of their 20 years. The symptoms of vision slowly get worse over approximately 10-20 years.

Usually, keratoconus affects both eyes and can generate a different vision in them. The symptoms may be different in each eye and vary over time.

In the early stage, the symptoms of keratoconus can be:

mild blurred vision
slightly distorted vision, where straight lines look bent or wavy
greater sensitivity to light and glare
redness or swelling in the eyes
In the more advanced stages, the symptoms of keratoconus can be:

Vision more blurred and distorted.
Increased myopia or astigmatism (when the eye cannot focus as well as it should).
As a result, you may need to change the prescription of the glasses frequently.
Not being able to wear contact lenses. They may no longer fit properly and feel uncomfortable.
Keratoconus usually takes years to move from early to advanced stage. However, in some people the keratoconus can get worse quickly. The cornea may suddenly swell and begin to heal. When the cornea has scar tissue, it loses its softness and becomes less transparent. As a result, vision becomes even more distorted and blurred.