When in the connective tissues surrounding our eyes there is an inflammation or edema (excess fluid), then is happening a condition which is known as swollen eyelid. Swollen eyes can be non – painful or painful and they are affecting the both lower and upper eyelids. There are many causes for swollen eyes such as allergies (that are the most common cause for swollen eyes), eye injuries or trauma and eye infections. Also there are some cases when the swelling of the eyelid are a sign of more serious and potentially sight – threatening health problems such as ocular herpes, Grave’s disease and orbital cellulitis. If you have noticed that your symptoms are persistent, they are worsening or they are changing, then it is very important to visit your eye doctor who will make an eye exam to be sure about the cause for this condition. In many cases people are confusing the term “swollen eyes” with the term “puffy eyes”. People think that the swollen eyes are the same condition with the puffy eyes but in fact it is not. “Puffy eyes” is a term that is used to connect with external physical characteristics of swollen eyes from genetic traits like dark circles under the eyes or a lack of sleep and water retention. “Swollen eyes” is a term which is used to describe an immune response to injury, infection or allergy.
When we have swelling of the eyelids, then this means that we have some underlying cause for it such as infection or allergy. When we have swollen eyes, then they are accompanied with many symptoms such as
- Pain, particularly when swollen eyelids are caused by infection
- Eyelid dryness or flaking
- Eye discharge or mattering
- Red eyes and inflammation of the conjunctiva
- Redness of the eyelid
- Obstructed vision (depending on the extent of the swelling)
- Excess tear production which is resulting in water eyes
- Eye irritation such as scratchy or itchy sensation
Causes of swollen eyes: There are many causes of swollen eyelids which can range from mild to potentially sight – threatening conditions. Here are some causes of swollen eyes:
- Allergies: Eye allergy occurs when our immune system is overreacting to a foreign substance which is known as allergen. The most common eye allergens are contact lens solutions, certain eye drops, dust and pollen. 
- Styes: They are caused by bacterial infection and inflammation of a meibomian gland. They usually appear as reddish and swollen bump on your eyelids edge. 
- Conjunctivitis: This is an inflammation of the clear lining of the surface of your eye. Also it is known as pink eye. 
- Chalazion: This condition is also caused by a blocked meibomian gland. In the first stages it mimics a stye but in the later stages it develops into a hard sebaceous cyst. 
- Eye injuries: Any kind of trauma to the eye area can trigger swollen eyes and inflammation. 
- Contact lens wear: If you are wearing dirty lenses, storing in a contact in a dirt lens case or swim with contact lenses, then this can cause swollen eyelids and eye infection. 
- Blepharitis: This is an inflammation of your eyelids which is usually caused by malfunctioning of the oil glands in your lids that empty near your eyelashes base. This condition is characterized by painful and swollen eyelids and they can be accompanied with the loss of eyelashes and dandruff – like flaky eyelid skin. 
- Ocular herpes: Ocular herpes is the most common herpes simplex virus which in many cases is dubbed – the cold sore of the eye. This condition causes inflammation of the cornea but also there are some cases when it causes scarring. These symptoms can be very similar to the pink eyes but also you can feel painful sores on your eyelids. Also you can have a blurry vision due to a cloudy cornea.
- Grave’s disease: This is an ocular disorder that is stemming from an overactive thyroid. It is often associated with pussy and swollen eyelids as well as drooping eyelids and double vision. 
- Orbital cellulitis: This is a rare bacterial infection which can be very serious. It is a bacterial infection of the tissues surrounding your eyes which is resulting in painful swelling of your lower and upper eyelid and possibly the cheek and the eyebrow. 
- Periorbital cellulitis: This is a very common inflammation and infection of your eyelids and portions of skin around your eyes. This infection can be caused by viruses, bacteria or other pathogens.
Above are some of the causes of Swollen eyes.
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