Ptosis (pronounced “TOE-sis”) is a drooping of the upper eyelid. It can affect one or both eyes, ranging from a barely noticeable drop to a lid that hangs low enough to block your vision. The condition happens when one or both of the muscles responsible for lifting the upper eyelid stop working properly.
How the Eyelid Normally Stays Open
Two muscles work together to hold your upper eyelid in position. The primary lifter is a striated muscle about 40 mm long that connects to the eyelid through a flat, tendon-like sheet called an aponeurosis. This muscle does the heavy lifting, and the brain controls it through the third cranial nerve. A second, smaller smooth muscle sits just beneath it and adds roughly 2 mm of additional lift. This smaller muscle is controlled by the sympathetic nervous system, the same branch that governs your fight-or-flight response.
When either muscle weakens, loses its nerve supply, or physically detaches from the eyelid, the lid drops. Which muscle is affected, and why, determines the type and severity of ptosis.
Types and Causes
Aponeurotic Ptosis
This is the most common form in adults. Over time, gravity and normal aging stretch the tendon-like tissue that connects the main lifting muscle to the eyelid. The muscle itself may still work fine, but because the connection has loosened or partially detached, the lid sags. Chronic inflammation, previous eye surgery, trauma, and long-term hard contact lens wear can all accelerate this process. Most cases produce mild to moderate drooping.
Neurogenic Ptosis
Damage to the nerves controlling the eyelid muscles causes this type. When the third cranial nerve is affected, perhaps by a brain aneurysm, compression, or stroke, the drooping is usually severe or complete because the main lifting muscle loses its signal entirely. In contrast, Horner syndrome disrupts the sympathetic nerve fibers that control the smaller muscle, producing only mild ptosis along with a smaller pupil on the same side.
Myogenic Ptosis
Here the muscle itself is the problem. Conditions like myasthenia gravis (where the immune system attacks the connection between nerves and muscles), muscular dystrophy, and certain mitochondrial diseases can all weaken the eyelid-lifting muscle directly. These causes tend to be progressive, and even after surgical correction the drooping frequently returns.
Mechanical Ptosis
Sometimes the eyelid is simply too heavy for the muscles to hold up. Tumors on the eyelid, excess fat prolapse, or chronic swelling can all add enough weight to drag the lid down. The muscles are functioning normally but are overwhelmed.
Traumatic Ptosis
A direct injury to the eye area can tear or detach the lifting muscle, damage the tendon, or injure the third cranial nerve. Scar tissue may form afterward, creating a secondary mechanical ptosis on top of the original damage.
Ptosis vs. Excess Eyelid Skin
Not every droopy-looking eyelid is true ptosis. A condition called dermatochalasis, excess eyelid skin that sags over the lid margin, creates a similar “tired” or “hooded” appearance but involves a different problem entirely. In dermatochalasis the eyelid muscle is lifting the lid to the correct height; it’s the skin above that’s drooping over it. The distinction matters because the treatments are different: ptosis requires a repair of the muscle or its attachment, while excess skin is addressed by removing the redundant tissue through a procedure called blepharoplasty.
When Ptosis Signals Something Serious
In many cases, ptosis is a standalone cosmetic or functional issue. But it can also be the first visible sign of a more dangerous condition. Horner syndrome, which causes mild ptosis along with a constricted pupil, can result from a stroke, a lung tumor, damage to the aorta, or a spinal cord injury. Third nerve palsy, which causes severe ptosis often paired with double vision and a dilated pupil, can signal a brain aneurysm or bleeding around the brain.
Seek emergency care if ptosis appears suddenly, follows a traumatic injury, or comes with any of the following: impaired vision, dizziness, slurred speech, difficulty walking, muscle weakness, or a severe sudden headache or neck pain. These combinations suggest the drooping eyelid may be a symptom of something that needs immediate attention.
Ptosis in Children
Congenital ptosis is present from birth, typically because the main lifting muscle didn’t develop properly. The concern with children isn’t just cosmetic. A drooping lid can physically block the pupil, preventing light from reaching the retina during the critical years when the visual system is still developing. This can cause amblyopia, sometimes called “lazy eye,” where the brain never learns to process images clearly from the affected eye. Even when the lid doesn’t fully cover the pupil, its weight can press on the eye’s surface and create astigmatism, which also contributes to amblyopia.
Estimates suggest that 20 to 70 percent of children with simple congenital ptosis will develop amblyopia, which is why early surgical correction is often recommended when the lid is low enough to threaten vision. In milder cases where the visual axis remains clear, surgery can be safely postponed until the child is 3 to 5 years old, giving the face time to grow and making preoperative measurements more reliable. Children may also develop a chin-up head tilt, called ocular torticollis, as they unconsciously try to see beneath the drooping lid.
Treatment Options
Eye Drops
For mild acquired ptosis, a prescription eye drop containing oxymetazoline is available. Applied once daily to the affected eye, it works by stimulating the smaller eyelid muscle to contract, providing a modest lift. It won’t fix the underlying cause, but it can reduce the droop enough to improve appearance and comfort throughout the day. It’s approved for adults and children 13 and older.
Surgery
When ptosis is moderate to severe, or when it blocks vision, surgery is the standard approach. The specific technique depends on how well the lifting muscle still functions.
If the muscle retains reasonable strength, the surgeon typically shortens it or reattaches its tendon to the eyelid, restoring the connection that holds the lid at the right height. This is the most common repair for age-related aponeurotic ptosis.
If the muscle is very weak, with only about 2 mm or less of function remaining, a different approach called frontalis suspension is used. This procedure connects the eyelid to the forehead muscle with a sling material, allowing you to raise the lid by raising your brow. The gold standard sling material is a strip of tissue harvested from the patient’s own leg, though synthetic options like silicone thread are increasingly popular, especially for young children or patients who want to avoid a second surgical site.
For patients whose ptosis followed a recent nerve injury or trauma, surgeons typically recommend waiting 6 to 12 months before operating. This window allows time for spontaneous recovery. Patients with dry eyes, reduced corneal sensitivity, or limited ability to roll the eye upward during blinking are at higher risk for corneal exposure after surgery, so their lid height may be intentionally set a bit lower to protect the eye’s surface.