As we would see in humans, glaucoma is a condition in which the pressure in the eye is increased due to inadequate draining of aqueous fluid. This destroys the optic nerve and retina. Symptoms include eye pain, watery discharge, lethargy, loss of appetite, noticeable swelling and bulging of the eyeball, and blindness. Once your vet diagnoses, medication or surgery can be prescribed to treat this degenerative disease.