Droopy Eyelid (Ptosis): Causes, Red Flags and Treatment

Ptosis (pronounced toe-sis) is the medical term for a drooping upper eyelid. It can affect one or both eyes, be barely noticeable or cover the pupil enough to block vision, and it can be present from birth or appear later in life. Many people first notice it in photographs, or when they find themselves raising their eyebrows or tilting their head back to see from under a heavy lid.

Most cases in adults are caused by gradual stretching of the tendon that lifts the eyelid, a common age-related change that can be corrected with surgery. However, a droopy eyelid is sometimes the first sign of a problem with the nerves or muscles, and a few causes need urgent medical attention. This guide explains the types and causes of ptosis, the warning signs that should never be ignored, how it is assessed and the treatment options for children and adults.

How the eyelid is lifted

Two muscles raise the upper eyelid. The main one, the levator palpebrae superioris, is controlled by the third cranial nerve (oculomotor nerve), the same nerve that moves most of the eye muscles and constricts the pupil. It attaches to the eyelid through a broad, flat tendon called the levator aponeurosis. A smaller muscle, Müller's muscle, adds a couple of millimetres of lift and is controlled by the sympathetic nervous system, the same system that widens the pupil. Our guide to the anatomy of the eye shows these structures.

Anything that weakens these muscles, stretches the tendon, interrupts their nerves or physically weighs down the lid can cause ptosis.

Congenital ptosis

Congenital ptosis is present at birth or appears within the first year. In most cases the levator muscle has not developed normally and contains fibrous tissue, so it neither lifts well nor relaxes fully. Typical features include a lid crease that is faint or absent and a lid that may not close completely or lag behind when looking down.

The main concern in children is vision. If the eyelid covers the pupil, or presses on the eye and causes astigmatism, the brain may not receive a clear image from that eye during the critical period of visual development, which can lead to amblyopia. Children with ptosis often tilt their head back or lift their eyebrows to see. They need assessment by a paediatric ophthalmologist, glasses or patching if amblyopia develops, and surgery if the lid blocks vision. See our guide to strabismus and amblyopia and eye health in children.

Acquired ptosis

Acquired ptosis develops later in life. Doctors usually group it by cause:

Aponeurotic ptosis

This is by far the most common type in adults. Over the years, the levator tendon thins, stretches or partly detaches from the eyelid. The muscle itself still works, but its pull is not transmitted fully to the lid. Risk factors include ageing, long-term rigid contact lens wear, frequent eye rubbing, and previous eye surgery such as cataract surgery, where the lid speculum and swelling can stretch the tendon. It typically develops slowly and may affect both eyes. Our guide to contact lenses includes advice on safe long-term wear.

Pseudoptosis: when the lid only looks droopy

Not every heavy-looking eyelid is true ptosis. Excess skin of the upper lid (dermatochalasis), a drooping brow, a small or sunken eye, or the other eye being too open, for example in thyroid eye disease, can all create the appearance of ptosis. Distinguishing these matters because the treatment differs: excess skin is treated with blepharoplasty, while true ptosis needs a procedure on the lifting muscle.

Myasthenia gravis

Myasthenia gravis is an autoimmune condition in which antibodies interfere with the signals passing from nerves to muscles. The eye muscles are frequently the first to be affected. Clues include:

• Ptosis that varies over the day, is better in the morning and worse in the evening or with tiredness.
• Ptosis that switches from one side to the other.
• Double vision that comes and goes.
• Fatigue on sustained upgaze: the lid gradually drops when looking up for a minute or so.
• Sometimes weakness in chewing, swallowing, speech, the neck or limbs.

Diagnosis involves blood tests for specific antibodies, nerve conduction studies and sometimes a simple ice-pack test in the clinic, because cold temporarily improves the ptosis. Treatment, usually led by a neurologist, uses medicines that improve nerve-muscle signalling and medicines that calm the immune system. Breathing or swallowing difficulty in myasthenia is an emergency.

Horner syndrome

Horner syndrome results from disruption of the sympathetic nerve pathway, which travels from the brain down the spinal cord, over the top of the lung and up the neck alongside the carotid artery to the eye. Its classic features are:

• Mild ptosis, usually only 1 to 2 millimetres.
• A smaller pupil (miosis) on the same side, most obvious in dim light.
• Sometimes reduced sweating on that side of the face.

Horner syndrome can be caused by harmless or long-standing conditions, but it can also signal serious ones, such as a tear in the wall of the carotid artery (carotid dissection), a tumour at the top of the lung, or problems in the brainstem or neck. A new Horner syndrome, especially with neck, face or head pain, needs same-day assessment and imaging.

Third nerve palsy: an important red flag

The third cranial nerve controls the main eyelid muscle, most eye movements and pupil constriction. When it is damaged, the result is often marked ptosis, an eye that turns down and out, double vision and sometimes a large (dilated) pupil that reacts poorly to light.

Third nerve palsy has several causes. In older people with diabetes or high blood pressure, it is often due to reduced blood flow to the nerve and usually recovers over weeks to months. But a third nerve palsy, particularly one involving the pupil, can also be caused by an aneurysm, a bulging blood vessel in the brain pressing on the nerve, which can rupture and is life-threatening. For this reason, any new third nerve palsy needs urgent evaluation and usually brain imaging.

Other causes

• Botulinum toxin injections for wrinkles can occasionally spread to the lid muscle and cause temporary ptosis that resolves over weeks.
• Eyelid swelling from infection, allergy, a chalazion or trauma.
• Lid tumours that weigh the lid down.
• Chronic progressive external ophthalmoplegia and muscular dystrophies, which cause slowly progressive ptosis in both eyes and limited eye movement.

How ptosis is assessed

An ophthalmologist, often an oculoplastic (eyelid) specialist, will take a careful history, including when the ptosis started, whether it varies during the day, any double vision, contact lens wear, previous surgery or injuries, and general health. Examination includes:

• Measuring the height of the lid relative to the pupil (margin reflex distance) and the height of the lid opening.
• Measuring levator function: how far the lid travels from looking down to looking up.
• Checking the lid crease, eye movements, pupils and corneal sensitivity.
• Checking for Bell's phenomenon, the upward roll of the eye on closing, which protects the cornea after surgery.
• Visual field testing, often with the lid taped up, to measure how much the lid blocks vision.

Depending on findings, blood tests, nerve tests or imaging may be arranged. Our guide to eye examinations explains common tests.

Treatment options

Treatment depends on the cause. When ptosis is caused by an underlying condition, such as myasthenia gravis or a nerve palsy, that condition is treated first, and many cases improve. Surgery is offered when ptosis is stable and affects vision, comfort or appearance.

Surgery

Adult ptosis surgery is usually performed under local anaesthetic, sometimes with sedation, so the surgeon can ask you to open your eyes and adjust the lid height during the operation. Recovery involves bruising and swelling for one to two weeks. Possible issues include under- or over-correction, asymmetry, a temporary difficulty closing the eye fully leading to dryness, and occasionally the need for revision. Our eye surgery options guide covers what to expect from eyelid operations in general.

Non-surgical options

For people who cannot have surgery, a ptosis crutch, a small bar attached to the glasses frame that props up the lid, can help. In some countries, prescription eye drops containing oxymetazoline are approved for acquired ptosis; they stimulate Müller's muscle and lift the lid by a small amount for several hours. These are only suitable for selected mild cases and should be prescribed by a doctor after the cause has been established.

When to see a doctor

See your doctor or an eye specialist if you notice a gradual droop of one or both eyelids, if a lid is affecting your vision or causing you to tilt your head or strain your forehead, or if your child's eyelid droops at any age. Parents should seek early assessment because amblyopia is preventable when treated in time.