Can excessive crying from extreme sadness cause blindness?

In general, excessive grief and prolonged crying usually do not directly cause blindness, but they may trigger short-term or long-term eye health issues. A comprehensive assessment based on symptom severity and potential causes is necessary.

During crying, the lacrimal glands secrete large amounts of tears, causing blood vessels to dilate and resulting in red eyes due to conjunctival congestion. The eyelid skin is thin and loose, and tear retention and local fluid exudation may lead to swelling, which typically resolves spontaneously within several hours to one day after crying stops. The salt and proteins present in tears may leave behind residue and crystals after evaporation, temporarily affecting the corneal refractive power and causing mild vision reduction, which can be relieved by blinking or using artificial tears.

Excessive crying may disrupt the balance of tear composition, accelerating water evaporation and reducing mucoproteins, thus destabilizing the tear film and potentially causing dry eye symptoms such as stinging, foreign body sensation, and light sensitivity. Additionally, it's important to note that intense emotional fluctuations may lead to autonomic nervous system dysfunction, causing pupil dilation, angle closure, a sudden increase in intraocular pressure, and triggering acute angle-closure glaucoma.

Although excessive crying due to intense sadness does not directly cause blindness, to protect eye health, it is advisable to avoid prolonged crying or excessive emotional excitement, and to regulate emotional states promptly. If eye discomfort such as pain, redness, or blurred vision occurs during crying, timely medical evaluation is necessary to rule out the possibility of ocular diseases.