What is the most common cause of mucous fishing syndrome?

Mucous fishing syndrome primarily arises from dry eye syndrome. This condition is characterized by inadequate tear production or poor tear quality, leading to dryness and discomfort in the eyes. As a result of this dryness, patients frequently experience a sensation of foreign body presence, which may prompt them to rub their eyes or remove mucous discharge that accumulates, leading to a cycle of irritation and further mucous production.

In individuals with dry eye syndrome, the body often compensates for the lack of effective tear film by producing more mucous for lubrication. This increased mucous can then create a persistent cycle where the patient continuously attempts to relieve the discomfort, leading to the characteristic behavior of 'fishing' for mucous. While other conditions like allergic conjunctivitis, blepharitis, and contact lens irritation can cause eye discomfort and mucous discharge, they do not inherently create the same syndrome of dependence and response as seen in dry eye syndrome. Therefore, understanding the underlying mechanism of mucous production and its relationship to dry eye syndrome highlights why it is identified as the most common cause of mucous fishing syndrome.