Pannus (Persistent superficial keratitis, or PSK ) emerges as a grey, pink film that spreads across the eyes. It can lower or eliminate your pet's vision. As the changes spread all over the cornea, vision is influenced. As the disease advances, the cornea will become opaque. Over time, this can lead to blindness. If your pet is suffering from this devastating disease, this concise book tells you all you need to know about the causes of the disease and treatment options.