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
| Type of Glaucoma | Key Symptoms |
| Open-angle | Slow peripheral vision loss, tunnel vision |
| Angle-closure | Sudden pain, haloes, blurred vision, nausea |
| Normal-tension | Vision loss with normal IOP, often unnoticed |
| Secondary | Depends on underlying condition (pain, redness) |
| Congenital | Cloudy eyes, tearing, light sensitivity in infants |
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.
