A swollen eye is a relatively common symptom. The swelling could be generalized (involving the whole eye) or localized (involving a part of the eye).
There are many causes of a swollen eye. While some causes like allergies, crying and fatigue are self-limiting and usually do not result in complications, a swollen eye can sometimes be a symptom of vision-threatening conditions (like orbital cellulitis and Graves ophthalmopathy) which require prompt attention by an eye doctor.
A swollen eye may be accompanied by other symptoms like redness, itching, discharge, burning and gritty sensation.
Causes of swollen eye
- Fatigue and lack of sleep: When you do not sleep well at night, the surrounding skin may retain water overnight making them look puffy on waking up. The eyes can also swell up when they are tired.
- Crying: When you cry, blood flow to your eyelids and the surrounding skin may increase and lead to fluid retention giving the eyes a puffy appearance.
- Infective conjunctivitis: The eyelids get swollen when you have bacterial and viral conjunctivitis. This is due to the inflammation of the conjunctival lining of the inner surfaces of the lids.
- Allergy: Exposure of the eyes to allergens like pollen, molds, dust and smoke can cause allergic reactions that result in itching, redness and swelling. This can also occur with the use of some cosmetics like eyeliners and creams.
- Stye and chalazion: A stye is a painful localised inflammation on the lid caused by blocked meibomian gland ducts. If stye is infected, the swelling may be accompanied by discharges. A chalazion is also a localised hard swelling on the lid but unlike stye, does not cause pain.
- Blepharitis: This is an inflammation of the eyelid caused by some bacteria and eye mites on the eyelid. The eyelids are usually red, swollen and itchy. There may also be dandruff like substances or crusts on the eyelashes.
- Floppy eyelid syndrome: In floppy eyelid syndrome, the upper lids are weak and tend to flip so easily especially during sleep. This can cause some inflammation of the upper eyelid resulting in swelling and redness.
- Trauma: Trauma to the eyeball can cause the tissues of the eye and surrounding skin to get inflamed. Blood vessels of the skin may also rupture causing blood to flow out of them into the spaces between the skin layers resulting in a swollen black eye.
- Cellulitis of the eyes: Cellulitis is a bacterial infection affecting the inner layers of the skin including the fat layer and other layers beneath it. This infection can affect the skin and tissues in and around the eyes. Cellulitis of the eyes are two types namely – preseptal cellulitis and orbital cellulitis. Preseptal cellulitis affects the eyelid and tissues in the front part of the eye. Orbital cellulitis on the other hand involves the deeper structures of the eye. It is more serious than preseptal cellulitis and can be life-threatening if the infection gets to the brain. In both conditions, there is generalized redness and swelling of the eyes. However additional symptoms such as fever, restriction of ocular movement, bulging eyeball (proptosis) and poor vision occur in orbital cellulitis.
- Dermatochalasis: Dermatochalasis, also called baggy eye is a condition where there is excess skin on the lower and upper eyelids caused by laxity of the eyelid muscles and skin. It is normally seen in the aged and occasionally in young adults. In some cases, orbital fats may seep into the excess skin leaving a yellow patch on the eyelids (orbital fat prolapse).
What to do when you have swollen eyes
Most swollen eyes are self-limiting and resolve without treatment. For cases that require treatment, the recommendation by your eye doctor will depend on the conditions causing the swelling.
Swollen eyes due to fatigue and lack of sleep will respond to rest and sleep. Those due to allergy may require anti-allergic medication to resolve. Cases due to blepharitis would respond to eyelid hygiene and antibacterial ointments. If a swollen eye is due to a non-vision threatening trauma, cold compresses may help.
If you have swollen eye associated with blurry vision, pains, discharges and/or bulging eyes, see the eye doctor immediately for proper diagnosis and treatment.