Vision starts with a functional, clear cornea (the front ‘window’ of your eye). Without a clear cornea the rest of the refractive media in the eye, like the lens, cannot function properly. Correcting corneal irregularities can improve your vision.
Keratoconus is when the cornea thins out and bulges like a cone. Changing the shape of the cornea brings rays out of focus. As a result, your vision is blurry and distorted, making daily tasks like reading or driving difficult.
Fuchs' dystrophy is a disease of the cornea. It is when cells in the epithelial corneal layer die off. These cells pump fluid from the cornea to keep it clear. When they die, fluid builds up and the cornea gets swollen. Vision becomes cloudy or hazy.
The cornea can become damaged or injured by trauma, infection or disease. If scar tissue forms, you can develope blurry vision. This is because the corneal scar may distort, scatter or block light from refracting onto the lens and retina properly.