Corneal sensations are diminished in:
Herpes simplex infection is a common cause of corneal sensory loss, although less severe than in keratitis caused by reactivation of varicella-zoster virus. Some patients with active HSV keratitis present with sensations of spontaneous pain, discomfo, and dryness.
Herpes simplex
Conjunctivitis
Fungal infections
Marginal keratitis
Diseases of Cornea