The eyelid

Eyelids are something that most people take for granted. We see their function as protecting the eyes and allowing us to sleep. However, eyelids play a far greater role in maintaining good vision than most realise. In basic terms, the eyelid is a fold of skin (in fact two folds consisting of the upper and lower eyelids). They are the thinnest skin on the body. Connected to the eyelid is a muscle that is responsible for the opening and closing of the lid – this can be voluntary (such as sleeping) or involuntary (blinking).

The role of the eyelids

The main role of the eyelids is to protect the eye. It’s vital that the surface of the eye (the cornea) remains constantly moist, so the eyelid is responsible for spreading the tear film evenly across the surface. When we sleep, the eyelids don’t simply block out light, they keep the cornea from drying out. Ancillary to the eyelids are the eyebrows, which protect the eyes from dirt, debris and sweat, and the blink reflex, which protects the eyes from foreign bodies.

What can go wrong?

Although physically small, eyelids are actually complex components made up of layers of skin, muscle, ligaments, nerves, blood vessels and fat. Because of this intricate structure and their exposure to the elements, the eyelids are prone to a number of disorders:

• Ptosis. The drooping of the upper eyelid. Treatment depends on the severity but may include surgical correction.
• Stye. An infection of the sebaceous glands. A stye is indicated by a red, occasionally painful and swollen bump on the eyelid. These usually disappear slowly on their own within a week, however occasionally antibiotics will need to be prescribed.
• Chalazion. Caused by the inflammation of a blocked oil gland in either the upper or lower lid. This is often mistaken for a stye but is a more chronic condition. Usually treated by topical ointments or surgery.
• Blepharitis. Chronic inflammation of the eyelid. Symptoms include a burning sensation, excessive tearing, blurred vision, light sensitivity, red and swollen eyelids. In severe cases there can be crusting of the eyelashes upon awakening. Treatment is usually as simple as good eye hygiene, however antibiotics may occasionally be prescribed.
• Entropion/ectropion. A condition where the eyelid folds forward (entropion) or outwards (ectropion). There are a number of treatments, depending on the severity of the condition, ranging from eyedrops to surgery.
• Eyelid tumours. These can be either benign or malignant, and depending on the size, position, and speed of growth, may need to be removed and assessed for malignancy.

Cosmetic eyelid surgery

Called a blepharoplasty, cosmetic eyelid surgery is becoming increasingly popular. No surgical procedure is without risks and cosmetic eyelid surgery tends to be very expensive. A blepharoplasty can also be performed for medical reasons, including treatment for ptosis, tumours and other eyelid related disorders.

Conclusion

More than just a canvas for make-up, the eyelid is a powerhouse of a component, shielding, wiping and cleaning the cornea. Attend to good eyelid hygiene and the eyelid will reward you with good eye health.