Corneal dystrophies are varied and can reach different structures of the cornea (more or less deep).
Lipidic dystrophies correspond to cholesterol cristal deposits in the cornea. It isn’t serious, as it does not have an impact on sight.
Endothelial dystrophies are more serious as they can lead to a progressive opacification of the cornea by creating a corneal oedema.
Surgical treatments do exist. Any opacity of the cornea must encourage an owner to see his veterinarian.