Don't mistake this complex condition for a more typical ocular surface disorder. One of the most common complaints we encounter in the clinical setting is ocular discomfort, typically in the form of dryness, irritation and foreign body sensation. These annoying symptoms are among the most pervasive and vague. While dry eye syndrome is an exceedingly prevalent diagnosis in our adult population, we must differentiate aqueous deficiency or evaporative dry eye from more complex and, potentially, refractory conditions. Filamentary keratitis is one such condition.