On physical exam, findings will depend on the stage of the disease. Early manifestations in the cornea can be seen as punctate keratopathy, pseudodendrites, and epithelial or subepithelial corneal deposits.[10] These features can lead an examiner to confuse AK with a viral keratitis, such as that cause by Herpes zoster virus or Herpes Simplex Virus.[20] As the disease progresses and infiltrates the corneal stroma, a classic "ring infiltrate" may be present on examination (although this is only seen in about 50% of cases).[10][11] Corneal ulceration, or in severe cases, perforation, can also occur and may be accompanied by hypopyon.[11][21]