Tearlessness occurs when the lacrimal glands are not developed congenitally, or due to an acquired autoimmune system disorder that disrupts lacrimal secretion, resulting in the desire to cry without tears. Tearlessness is an eye disease that cannot be cured, and patients can only rely on medicated ointments to improve symptoms or use special moisturizing glasses to avoid water evaporation. It is caused by chronic inflammation affecting the muscular nerve of the lacrimal duct, which reduces the contraction of the duct, and by inflammatory infiltration around the duct, which weakens the duct wall, and by inflammatory stimulation, which increases tear secretion and causes the duct to expand passively and form a cyst. Lacrimal gland is absent or underdeveloped. Abnormal nerve reflexes for tear secretion or failure to establish a connection between the central nerve pathway and the lacrimal nucleus. It can also be seen in familial autonomic dysplasia, etc. Congenital atelectasis refers to a congenital underdevelopment or underdevelopment of the lacrimal glands, often bilateral, in which the infant is born without tear secretion, even if stimulation does not cause tear secretion. The clinical manifestations are photophobia, corneal dryness, photophobia, conjunctival congestion, and punctate infiltration of the corneal epithelium and superficial parenchymal layer due to the absence of tear wetting.