What is the difference between a corneal erosion and a corneal abrasion?

Erosion is deeper: Corneal abrasion is a scratch that damaged the top layer of cells on the cornea. Often after a doctor checks it, antibiotic drops are used, and the abrasion heals in 1-2 days without a scar. A corneal erosion or ulcer is a deeper injury, beyond the top layer of cells. The eye doctor will see damage to a deeper layer in the cornea. Stronger, more frequent antibiotics are used, and a scar may form.

Basically the same: This is a semantics issue. An erosion and abrasion are a loss of the surface epithelium of the cornea, the front clear surface of the eye. They imply that there is no active infection. They are essentially treated the same. Often, an erosion occurs spontaneously without any trauma. A typical abrasion is precipitated by an injury to the eye such as a fingernail.