<prompt> Mucin tear film deficiency occurs inKeratoconjunctivitis siccaLacrimal gland removalCanalicular blockHerpetic keratitis  <response>: Ans. d Herpetic keratitisRef: Khurana anatomy, 2e, p. 389Soluble surfactant Mucin deficiency is caused by ocular surface disorders affecting the goblet cells which secrete mucus forming the innermost layer of the tear film. Herpes infection causes Keratoconjunctivitis and hence mucin deficiency. 