It is a degenerative disease of the eyes and occurs precisely in the cornea (which is the transparent face and anterior of the eye).
It make the cornea, during its evolution, to adopt a more curved shape than normal, producing an irregular cone and thinning it, due to the disruption that occurs in the internal structure of the corneal tissue, generating a significant visual distortion and other disturbances.
Normally this disease starts in the puberty between the ages of 8 and 15, but it can start at more advance ages. It could develop in one or both eyes and evolve at different degrades. It takes between 10 to 20 year to develop but sometimes it develops faster and then stops.
Image distortion, blurred vision at any distance and worse at night, photophobia (light sensitivity), glare, itching, irritation and eye fatigue, having to be looking away for a better view.
However in some patients the sensation of discomfort and pain could be minor or nonexistent.