Symptoms of Glaucoma

Symptoms of Glaucoma

The symptoms of glaucoma depend on the type and stage of the disease. In its early stages, glaucoma is often silent and symptomless, which is why it is commonly referred to as the “silent thief of sight.” Many people do not realise they have the condition until irreversible damage to their vision has already occurred. Recognising the different symptom patterns between the various types of glaucoma is crucial for timely diagnosis and prevention of vision loss.

In most cases, symptoms progress gradually, affecting peripheral vision first. However, certain types—such as acute angle-closure glaucoma—can cause rapid, painful symptoms that require emergency intervention. Understanding what to look out for, even in the absence of discomfort, empowers individuals to protect their eyesight through regular screenings and prompt action.

Symptoms of Primary Open-Angle Glaucoma

This is the most common form of glaucoma globally, accounting for approximately 70–90% of cases. It progresses slowly and often goes unnoticed for years.

Typical symptoms include:

Gradual loss of peripheral (side) vision

Tunnel vision in advanced stages

Difficulty adjusting to low light or glare

Blurred vision in the late stages

Because central vision remains intact until the disease is advanced, many people do not realise their peripheral vision is deteriorating. By the time vision loss is noticed, substantial and irreversible optic nerve damage may have already occurred.

Symptoms of Acute Angle-Closure Glaucoma

This type presents suddenly and requires urgent treatment to prevent permanent vision loss. It is less common but far more dramatic in presentation.

Common signs and symptoms include:

Severe eye pain, often in one eye

Redness of the eye

Blurry vision or haloes around lights

Sudden visual loss

Headache, especially on the affected side

Nausea and vomiting

This occurs when the drainage angle in the eye becomes abruptly blocked, causing a rapid rise in intraocular pressure. If not treated within hours, it can lead to permanent blindness. Anyone experiencing these symptoms should seek emergency medical attention.

Symptoms of Normal-Tension Glaucoma

Despite normal intraocular pressure, optic nerve damage still occurs in this form of the disease. The symptoms mirror those of open-angle glaucoma but may appear in people without the traditional risk of high eye pressure.

These symptoms include:

Gradual peripheral vision loss

Difficulty seeing in dim light

Occasional blurred or distorted vision

Because pressure readings may be normal, diagnosis can be delayed unless the optic nerve is thoroughly assessed during routine eye exams.

Symptoms of Secondary Glaucoma

Secondary glaucoma arises from other medical conditions, eye injuries, or medications. Symptoms vary depending on the underlying cause but may include:

Blurred vision

Eye pain or redness

Increased sensitivity to light

Visual disturbances related to inflammation, trauma, or cataract complications

Sometimes the symptoms of the primary condition—such as uveitis or steroid-induced IOP elevation—overshadow the signs of glaucoma, making early detection more challenging.

Symptoms in Congenital Glaucoma

This rare form affects newborns and infants. The signs may include:

Cloudy cornea

Excessive tearing (epiphora)

Enlarged eyes (buphthalmos)

Light sensitivity (photophobia)

Failure to thrive due to discomfort

Parents often notice that their infant has unusually large, shiny eyes. Prompt referral to a paediatric ophthalmologist is essential to prevent lifelong visual impairment.

Vision Loss Pattern in Glaucoma

Glaucoma typically affects peripheral vision first. As the disease progresses:

Vision loss extends towards the centre

Blind spots develop in the visual field

Tunnel vision becomes more pronounced

In the final stages, central vision is lost, potentially leading to complete blindness

Because this pattern of vision loss is painless and slow, people may adapt unconsciously—turning their heads more often or relying on the unaffected eye—without realising the extent of the damage.

Psychological and Functional Symptoms

As vision deteriorates, people with glaucoma may experience:

Difficulty reading or driving

Reduced mobility, especially in unfamiliar environments

Increased risk of falls or collisions

Anxiety, frustration, or depression due to declining independence

While vision cannot be restored, timely treatment can preserve what remains and slow the progression of symptoms.

Summary of Symptoms by Type

Conclusion | Symptoms of Glaucoma

The symptoms of glaucoma range from subtle and progressive to sudden and severe, depending on the type. Because early stages are often asymptomatic, regular eye examinations are essential—especially for those at increased risk. Early detection offers the best chance of preserving vision and maintaining quality of life.

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