Glaucoma
A group of eye conditions that damage the optic nerve, the pathway that connects the eye to the brain and allows us to see.
Understanding Glaucoma
Glaucoma is a group of eye conditions that damage the optic nerve, the pathway that connects the eye to the brain and allows us to see. While glaucoma is not a retinal condition, it is an important cause of vision loss and is often considered alongside other vision-related diseases because it affects the way visual information is transmitted.
The most common form of glaucoma is associated with increased pressure inside the eye (intraocular pressure), which can gradually damage the optic nerve. However, glaucoma can also occur when eye pressure is within the normal range.
Glaucoma often develops slowly and may not cause noticeable symptoms in its early stages. Because vision loss caused by glaucoma is usually permanent, early detection, regular eye examinations, and appropriate treatment are essential.
Retina International recognises the importance of understanding all conditions that affect vision and supports access to information, research, and communities that help people affected by vision loss.


What is Glaucoma?
Glaucoma refers to a group of progressive eye diseases that cause damage to the optic nerve.
The optic nerve contains millions of nerve fibres that carry visual information from the retina to the brain. When these fibres become damaged, areas of vision may gradually be lost.
Glaucoma-related vision loss often begins with peripheral (side) vision, and many people may not notice changes until significant damage has occurred.
There are several types of glaucoma, including:
- Primary Open-Angle Glaucoma (POAG) – the most common form, developing gradually over time.
- Angle-Closure Glaucoma – occurs when the drainage angle of the eye becomes blocked, causing a rapid increase in eye pressure.
- Normal-Tension Glaucoma – optic nerve damage occurs despite normal eye pressure.
- Secondary Glaucoma – develops as a result of another condition, medication, injury, or eye disease.
- Congenital or Childhood Glaucoma – rare forms that affect infants and children.
~76 million
people worldwide live with glaucoma
~50%
may not know they have it
1 in 2
could experience significant vision loss without appropriate detection and management
How Glaucoma can affect vision
Possible symptoms, particularly in more advanced disease, include:
- Loss of peripheral vision
- Difficulty seeing in low light
- Difficulty adjusting between light and dark environments
- Blurred vision
- Reduced visual field
- Eye pain, headache, nausea, or sudden vision changes in acute angle-closure glaucoma
Sudden symptoms such as severe eye pain, redness, nausea, or rapid vision loss require urgent medical attention.
Identifying Glaucoma
Eye Pressure Measurement (Tonometry)
Measures the pressure inside the eye.
Optic Nerve Examination
Allows clinicians to assess changes to the optic nerve.
Visual Field Testing
Measures areas of vision that may have been affected.
Optical Coherence Tomography (OCT)
Provides detailed images of the optic nerve and retinal nerve fibre layer.
Gonioscopy
Examines the drainage angle of the eye to determine the type of glaucoma.
Supporting individuals living with glaucoma
Eye Drops
Medications can reduce eye pressure by:
- Reducing fluid production
- Improving fluid drainage
Laser Treatment
Laser procedures may improve fluid drainage or reduce fluid production.
Surgery
Surgical options may be considered when other treatments are not sufficient.
Examples include:
- Trabeculectomy
- Glaucoma drainage devices
- Minimally invasive glaucoma surgery (MIGS)
Regular monitoring is essential to assess whether treatment is controlling disease progression.
Adapting to diagnosis
Living with glaucoma often involves ongoing management and regular eye care.
People affected may benefit from:
- Attending scheduled eye appointments
- Taking medications as prescribed
- Understanding changes in vision
- Using low-vision support services where needed
- Making adaptations to maintain independence
Because glaucoma can affect peripheral vision, some people may experience challenges with:
- Mobility
- Driving
- Navigating unfamiliar environments
- Reading and daily activities
Support from healthcare professionals and patient communities can help people adapt and maintain quality of life.

Advancing the future of glaucoma treatment
Early Detection
Researchers are developing improved imaging technologies and artificial intelligence tools to identify glaucoma changes earlier.
Learn About Early DetectionPersonalised Treatment
Studies are exploring how genetic, clinical, and imaging information can help tailor treatment approaches.
Learn About Personalised TreatmentNeuroprotection
Research is investigating ways to protect optic nerve cells from damage.
Learn About NeuroprotectionRegenerative Approaches
Future research aims to explore whether damaged optic nerve pathways can be repaired or restored.
Learn about Regenerative ApproachesInformation and community support
Take the Next Step
A diagnosis of glaucoma can raise questions about treatment, monitoring, and maintaining independence.
Support may include:
- Eye care professionals
- Vision rehabilitation services
- Low-vision resources
- Patient organisations
- Educational materials
Retina International’s global community connects people affected by vision loss with information, support networks, and opportunities to engage with research and advocacy.