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
A Vitamin A deficiency can lead to a thickening of the cornea and eventually even to blindness. Keratomalacia, a condition that comes from severe deficiency of vitamin A, is a condition that is bilateral, meaning it usually affects both eyes.