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 there is water retention in the cornea area, it causes corneal swelling, which leads to corneal edema. To keep the cornea dry and clear, the endothelium cells regularly drive out fluids from the cornea. This endothelium is made of a single layer of cells.