Why are my cats eyes watering all of a sudden?

Runny eyes may indicate that the cat has an allergy. Cats can be allergic to a variety of substances, such as pollen, dust, mold, chemicals or foods. Other signs that a cat may be suffering from an allergic reaction include sneezing and itchiness. Runny eyes in the form of an overflow of tears is known as epiphora.

Why is my cat crying tears?

While cat's tear ducts can create tears, they do this for medical reasons – not because your cat is sad. Cats crying tears can be a sign of debris, a scratch on your cat's eye, or other eye problems. Being left alone for long periods without enough stimulation can cause any apartment pet to feel bored and lonely.