Demodex is an ectoparasite commonly found in the human skin, and is observed in the great majority of those older than 70 years. Clinical significance of Demodex infestation in blepharitis remains debatable because it can be found in asymptomatic individuals. As a result, Demodex blepharitis is often overlooked in differential diagnosis of chronic blepharokeratoconjunctivitis. However, even minimal disruption of the ocular surface can severely degrade visual acuity. The main symptoms of demodicosis are itching, burning, foreign-body sensation, crusting and redness of the lid margin, and blurry vision. Presence of cylindrical dandruff is a classical sign of Demodex blepharitis.