When tears occur during sleep, it usually means that there is inflammation of the eye surface, lid ectropion, and blockage or narrowing of the tear duct, etc., as follows: a. Eye surface inflammation: inflammation of the eye surface, like the common conjunctivitis and keratitis, can bring tears into the tear duct normally through the blinking of the eyelids when the eyes are open during the day, so the tears are not very obvious. When the eyelids are closed during sleep, the circulation of tears may be impaired and there will be more tears. This inflammatory condition is usually accompanied by other symptoms, such as redness, increased discharge, hypertrophy of the lid margin, and possibly even impingement. Second, ectropion: Some of these are caused by lid ectropion, which is a variety of causes of lid ectropion, resulting in increased tearing caused by obstruction of the tear ducts into the tear dots. Third, there is a blockage or narrowing of the tear duct: there is a type of increased tearing that may be caused by a blockage or narrowing of the tear duct, and this tearing may be continuous.