They are different kinds of conditions. Bulging eye is the eye protruding from socket where it should be in for swelling of fat, tissue or muscle behind the eye. It can happen to one eye or both eyes. Because the swelling of tissue behind eyes, eyeballs are more protruding out, for space lesions. Because the cornea is more exposure to air than normal, so it makes eyes very dry and sensitive. Bulge could cause great pressure on optic nerves which might lead to vision loss finally. It is usually connected with some serious conditions, for example glaucoma, hyperthyroidism, leukemia and so on. The symptoms of bulging eye include extremely dryness and redness of eyes, protruding appearance of eyes and visible whiteness between the top iris and eyelid. As to swelling of eyes, it is usually connected to some disease, such as allergies, conjunctivitis, eye infections, styes and blepharitis. There are some daily movements which might cause eye swelling too, for example crying, poor sleeping and too much sodium in diet. It can be swelling eyes or eyelids. It is totally different appearance of the two diseases. Bulge is much deeper than simple swelling. Dryness is not a common symptom of swelling, on the contrary, swelling eyes can be watering. Hope this could help you.