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
When determining whether the corneal infiltrate is infectious or sterile, one helpful method is to divide the cornea into two distinct regions. Consider that the central cornea encompasses the 6mm of the cornea apex whereas the peripheral cornea is a 2mm to 4mm doughnut, with the limbus as its posterior border.