Why does ptosis develop — and what does it feel like? This guide explains the main causes of drooping eyelid, the symptoms people commonly experience, and what to watch for.
Ptosis occurs when the upper eyelid droops below its normal resting position. The drooping happens because the levator muscle — the primary muscle responsible for lifting the eyelid — is weakened, stretched, or receiving insufficient nerve signals. The specific cause varies by the type of ptosis and the age of the person affected.
In adults, the most common cause is involutional ptosis — the levator aponeurosis (the tendon connecting the muscle to the eyelid) gradually stretches and weakens with age. This produces a slow, progressive droop that worsens over months or years. It is entirely normal and very common after the age of 50.
Some people are born with ptosis due to incomplete development of the levator muscle during pregnancy. Congenital ptosis may be unilateral (one eye) or bilateral (both eyes) and ranges from mild to complete closure of the eyelid. It is the most common cause of ptosis in children.
Damage or disruption to the nerves controlling the eyelid muscles can cause ptosis. Key causes include third cranial nerve palsy (often from stroke, aneurysm, or diabetes) and Horner's syndrome (disruption of the sympathetic nerve pathway). Sudden onset neurogenic ptosis warrants urgent medical review.
Conditions such as myasthenia gravis, chronic progressive external ophthalmoplegia (CPEO), and myotonic dystrophy weaken the eyelid muscles directly. Myasthenia-related ptosis characteristically fluctuates — often worse in the evening or when tired.
Ptosis is a recognised complication of cataract surgery, LASIK, and other eye procedures. It occurs when the levator aponeurosis is disturbed during surgery or by the speculum used to hold the eye open. It may resolve on its own, or persist and require management.
Long-term contact lens use — particularly hard lenses — can cause repeated micro-trauma to the levator aponeurosis during insertion and removal over many years. This is a recognised contributing factor in ptosis among long-term contact lens wearers.
Direct injury to the eyelid, surrounding muscles, or the nerves that supply them can cause ptosis. Depending on the nature of the injury, this may be temporary or permanent.
A large chalazion (eyelid cyst), eyelid tumour, or significant swelling can physically weigh down the upper eyelid — causing what is called mechanical ptosis. Treatment of the underlying mass often resolves the drooping.
Ptosis can run in families. Some individuals have a genetic predisposition to weak levator muscles or connective tissue that predisposes them to early involutional changes. Family history of drooping eyelids is not uncommon.
The symptoms of ptosis range from subtle visual changes to obvious physical drooping. Some symptoms are visible to others; others are only felt by the person affected.
The upper eyelid sits lower than normal — either compared to the other eye (unilateral) or both sides appearing heavy and low (bilateral). In more significant cases the eyelid covers part of the pupil.
When the drooping eyelid encroaches on the pupil, the upper portion of the visual field is obscured. People may notice difficulty seeing overhead, reading signs, or catching movement from above.
To see under the drooping lid, many people unconsciously tilt their head back or adopt a "chin-up" posture. This is a classic compensatory sign that is often the first thing family members or doctors notice.
The effort required to keep a weakened eyelid open — often unconsciously using the brow or forehead muscles — causes significant fatigue, particularly by the afternoon or evening.
Constant use of the frontalis (forehead) muscle to compensate for the drooping lid leads to chronic brow aching and tension headaches — particularly across the forehead above the affected eye.
When only one eye is affected, the two eyes appear mismatched in how open or alert they look. This can affect confidence and be misinterpreted as tiredness or disinterest.
While most ptosis is gradual and benign, some presentations require urgent medical evaluation. The following are warning signs that should not be ignored:
Ptosis that appears suddenly — within hours or days — is not typical of age-related ptosis and may indicate a neurological cause. Seek medical review promptly.
Ptosis accompanied by double vision, outward eye deviation, or a dilated pupil may indicate third nerve palsy. This can be caused by an intracranial aneurysm — a medical emergency.
Significant ptosis in infants or young children should be assessed by a paediatric ophthalmologist early, as it can impair visual development. Do not wait and see.
We are an eyewear company, not a clinical service. This information is for general understanding only. Always consult a qualified ophthalmologist for diagnosis and advice on your specific situation.
For people with gradual ptosis who prefer to avoid surgery, or who are awaiting a clinical decision, ARTView ptosis crutch glasses provide a practical daily management tool. The built-in crutch mechanism gently holds the drooping lid at a normal height while the glasses are worn.