The most common cause of eyelid swelling is eye allergies. Eye allergies sometimes cause significant discomfort, often interrupting daily activities with annoying symptoms such as eyelid irritation and swelling. Eye allergies develop when the immune system overreacts to a certain allergen. When exposed to the allergen, cells in the eyes release histamines and other chemicals in an effort to protect the eyes, causing blood vessels inside the eyes to swell, and the eyes to become itchy, red and watery. Prescription medications are highly effective in relieving symptoms. Antihistamines often reduce eyelid swelling caused by allergies rather quickly.
A stye is caused by an inflammation and bacterial infection of the oil producing glands in the eyelid. Styes are sometimes itchy and tender to the touch. Styes usually appear as a reddish bump on the eyelid. When a stye first develops, the eye may feel bruised and may feel sensitive to light. A chalazion develops when one of these glands becomes blocked. The gland develops into a hard lump and may result in redness and swelling of the eyelid.
3. Pink Eye
Pink eye or conjunctivitis is an inflammation of the conjunctiva. The conjunctiva is a clear mucus membrane that lines the inside of the eyelid and covers the white part of the eye. Conjunctivitis is usually caused by allergies, bacteria or viruses. Patients may wake up to find one or both eyes stuck together with mucus when they wake up in the morning. The eyelids may become swollen, and the eyes may become red, itchy and irritated.
Cellulitis is a more serious cause of eyelid swelling. There are two main types of cellulitis that eye doctors concern themselves with when a patient comes in with eyelid swelling: preceptal cellulitis and orbital cellulitis.
Preceptal cellulitis is usually caused by a bacterial infection. Patients usually have redness and pain in addition to swelling. It usually occurs in one eye. Orbital cellulitis can also be caused by bacteria in the form of a sinus infection that invades the area around the bones that make up the eye socket. People with orbital cellulitis may have a bulging eye and pain when moving their eyes back and forth.
People with Graves' disease or other thyroid problems often suffer from eyelid swelling. Graves' disease can cause proptosis or bulging of the eyes. Although it can affect one eye more, it usually affects both eyes. Sometimes Graves' disease can cause reduced eye movements or double vision. Hypothyroidism can also cause both eyes to be somewhat swollen or puffy.
Eye herpes is an inflammation of the cornea, the clear dome that covers the front part of your eye. Eye herpes (also called ocular herpes) can produce painful sores on the eyelid or eye surface and cause inflammation of the cornea as well as eyelid swelling. Symptoms of eye herpes often mimic those associated with conjunctivitis. While a mild amount of facial swelling is normal when we wake up in the morning, severe eyelid swelling is not.
Sowka, Joseph W., Andrew S Gurwood and Alan G Kabat. The Handbook of Ocular Disease Management, Twelfth Edition, 15 April 2010, Supplement to Review of Optometry.