Corneal erosion is a very bad disorder of eyes. The epithlial layer of cornea failed to attach to the underlying membrane which is very excruciating because the extremely sensitive corneal nerves would be exposed. Corneal erosion probably comes from corneal abrasion, corneal ulcer, corneal dystrophy or corneal disease. It is hard to tell how long it will last, because the recovery time depends on severity and treatment. Averagely it will take weeks to heal up. Patients with corneal erosion will have increased sensitivity to light, eye pain, blurry vision, excessive tearing, and rough corneal epithelium, with map-like lines, dots, finger prints or microcyts. It might require surgical curative procedure. You should visit your ophthalmologist as soon as possible to ensure no worse or permanent damages to cornea is formed.