Effect of Chitosan-N-acetylcysteine on Subjective Pain Sensation in Corneal Abrasion

Inclusion Criteria: * Age older than 18 years * Corneal abrasion less than one third of the cornea Exclusion Criteria: * Ocular surgery within prior 3 months in the affected eye * Ocular injury within prior 3 months before abrasion in the affected eye * Ocular herpes of eye or eyelid within prior 3 months * Active ocular infection * Active ocular inflammation or history of chronic, recurrent ocular inflammation within prior 3 months * Ocular surface abnormality that may compromise corneal integrity * Presence of diseases that reduce experience of pain (e.g. Diabetes mellitus) * Pregnancy