Some birthmarks are from extra color (pigment) in the skin. Other birthmarks are blood vessels that are bunched together or don't grow normally. It's not clear why some children have birthmarks and others don't.
a thickening of the cornea may indicate swelling swelling usually occurs from damage to the back the layer of the cornea associated with aging trauma or disease of the eye the swelling can be observed for progression or medically treated with topical hyper osmotic agents
Degenerative corneal conditions Keratoconus, a rare degenerative condition which is inherited, causes a general thinning and an abnormal protrusion of the central cornea, as well as some scarring. Blurred vision results, and in advanced cases there may even be perforation of the cornea.