Drooping Eyelid (Ptosis): Causes and Red Flags

What a drooping eyelid looks like

Normally the upper lid rests 1 to 2 mm below the top of the colored part of the eye (the iris). In ptosis it sits lower and may cover part of the pupil. People notice:

• one eye looking smaller or "tired"
• difficulty seeing the top of the field of vision
• raising the eyebrows or tilting the head back to see
• forehead ache from constant eyebrow lifting
• in children, a head tilt or chin-up posture

Excess, sagging skin above the lid (dermatochalasis) can look like ptosis but the lid margin itself is in the normal position.

Causes of a drooping eyelid

Gradual, common causes

• Age-related (aponeurotic) ptosis: the tendon of the lifting muscle stretches or detaches with age. The most common cause in adults. Usually both sides, often one more than the other.
• Contact lens wear: years of inserting and removing hard or soft lenses stretch the tendon.
• After eye surgery: cataract, glaucoma or retinal surgery can cause ptosis.
• Eyelid swelling or masses: styes, chalazia, allergic swelling and growths can weigh the lid down.
• Congenital ptosis: present from birth, usually from a poorly developed lifting muscle.

Nerve causes (often sudden)

• Third nerve palsy: the third cranial nerve lifts the lid and moves the eye. Damage causes ptosis, an eye turned down and out, and double vision. A dilated pupil suggests compression, for example by an aneurysm, which is an emergency. Diabetes and high blood pressure cause a "microvascular" palsy that usually spares the pupil and recovers within 3 months. See cranial nerve palsy.
• Horner syndrome: damage to the sympathetic nerves causes a mild droop, a smaller pupil and sometimes less sweating on that side of the face. Sudden Horner syndrome with neck pain may mean a carotid artery tear; it can also come from lung-top tumors or stroke. See Horner syndrome.
• Stroke affecting the brainstem.

Muscle and neuromuscular causes

• Myasthenia gravis: an autoimmune condition that makes muscles tire with use. Ptosis worsens through the day or after prolonged upward gaze and improves with rest or ice. Double vision is common. It may spread to swallowing, speech and limbs.
• Muscular dystrophies, such as myotonic dystrophy and oculopharyngeal muscular dystrophy, which cause slowly progressive drooping on both sides.
• Botulism: rare, with drooping eyelids, double vision and descending weakness.

Other causes

Trauma to the lid, Botox injections near the brow (temporary droop for weeks), and long-term steroid eye drops.

Clues to the cause

How ptosis is assessed

A doctor or eye specialist measures how far the lid droops, how well the lifting muscle works, and the crease position. They check pupils, eye movements, facial strength and fatigue (asking you to look up for a minute). Depending on findings:

• urgent brain and blood vessel imaging (CT or MR angiography) for a third nerve palsy with pupil involvement or Horner syndrome
• blood antibody tests and an ice-pack test for myasthenia gravis
• visual field testing to document how much vision is blocked

For details on the types of ptosis and surgical correction, see ptosis.

Treatment

Treatment depends on the cause. Age-related and contact lens ptosis can be repaired with eyelid surgery, and prescription eye drops can lift the lid slightly for some adults. Myasthenia gravis is treated with medicines. Nerve palsies are treated according to their cause, and many microvascular palsies recover on their own. Children with ptosis that blocks vision need prompt treatment to prevent amblyopia (lazy eye).

Frequently asked questions

What causes a drooping eyelid in one eye?

The most common cause is stretching of the lifting tendon with age, contact lens wear or eye surgery. Others include a stye or swelling, Horner syndrome, third nerve palsy and myasthenia gravis. A droop that appears suddenly in one eye needs urgent assessment.

When should I worry about a drooping eyelid?

Seek emergency care if the droop is sudden and comes with a dilated or small pupil, double vision, severe headache, neck pain, facial or limb weakness, or difficulty swallowing or breathing. Gradual drooping is usually not dangerous but can be assessed routinely.

Can stress or tiredness cause a drooping eyelid?

Tiredness can make eyelids feel heavy and look slightly lower, especially at the end of the day. A droop that clearly worsens with fatigue and comes with double vision, though, is typical of myasthenia gravis and should be checked by a doctor.

Can a drooping eyelid go away on its own?

Sometimes. Drooping from swelling, a stye, Botox or a microvascular nerve palsy often improves over weeks to months. Age-related and congenital ptosis do not improve on their own and are treated with surgery if they affect vision or appearance.