Like dry eye disease 15 years ago, blepharitis today is a poorly defined condition about which there is considerable misunderstanding. For a variety of reasons, there is little good data on either the prevalence of blepharitis or how eyecare practitioners currently treat it. The work reported herein consists of two recent studies: a telephone survey of a representative sample of the adult US population (n = 5,000) whose purpose was to discover the frequency of common ocular surface symptoms associated with blepharitis; and a study that queried a selected group of ophthalmologists (n = 120) and a similarly selected group of optometrists (n = 84) about the frequency of blepharitis in their practices, the existence comorbid conditions, and their management strategies. This data suggests that blepharitis symptoms are very common in the US population, with younger individuals reporting more, and more frequent, symptoms than older people, contrary to clinical dogma. Ophthalmologists and optometrists report that blepharitis is commonly seen in clinical practice in 37% and 47% of their patients, respectively, and it is widely agreed that meibomian gland dysfunction (MGD) is the most common cause of evaporative dry eye disease. In addition, management paradigms are shifting away from more traditional management with antibiotic ointment and warm compress therapy to prescription therapy for anterior and posterior blepharitis. © 2009 Ethis Communications, Inc.