The main components of tears are water, salt, and many kinds of protein and other organic substances, and the water evaporates and leaves a yellowish “eye stool”. The lower valve of the nasolacrimal duct is not fully developed, which affects the normal circulation of tears, thus causing tearing. In addition, when the lacrimal sac is infected, dacryocystitis can also lead to abnormal secretions from the lacrimal sac, resulting in frequent lacrimation and excessive eye stools.