A pterygium doesn’t always cause symptoms. When it does, the symptoms are usually mild. Common symptoms include redness, blurred vision, and eye irritation. You might also feel a burning sensation or itchiness. If a pterygium grows large enough to cover your cornea, it can interfere with your vision. Thick or larger pterygium can also cause you to feel like you have a foreign object in your eye. You might not be able to continue wearing contact lenses when you have a pterygium due to discomfort.