Significant components of history include nature and duration of symptoms, preceding eye trauma, past medical history, and past ocular history. It is important to ask about previous eye surgeries, dry eye, poor lid function, trichiasis, periocular skin lesions, and immune status. A complete list of systemic and ocular medications, especially topical corticosteroids and local anaesthetics, should be elicited. If the patient is a contact lens wearer, determine lens care regimen and pattern of wear.