Why Half of All Glaucoma Cases Go Undiagnosed

Glaucoma is one of the leading causes of irreversible blindness worldwide, and Australia is no exception. According to Glaucoma Australia, an estimated 300,000 Australians are living with the condition. But here is the statistic that should concern everyone: roughly half of those people have no idea they have it. That means approximately 150,000 Australians are walking around right now with a progressive eye disease that is silently damaging their vision.

Understanding why so many cases slip through the cracks is the first step toward changing that figure.

The asymptomatic problem

The most common form of glaucoma, primary open-angle glaucoma (POAG), develops gradually over months and years. Unlike a sudden injury or an acute illness, there is no pain, no redness and no obvious warning sign in the early stages. The condition typically begins by affecting peripheral (side) vision, which most people do not consciously monitor in their daily lives.

Because the brain is remarkably good at compensating for subtle gaps in the visual field, people can lose a significant portion of their peripheral vision before they notice anything is wrong. By the time central vision is affected and the problem becomes obvious, the damage is often advanced and irreversible.

Why people don't present early

There are several reasons why people with early glaucoma rarely seek help on their own:

• No symptoms to prompt action. Without pain or noticeable vision changes, there is simply no trigger for most people to book an eye appointment.
• The "I can see fine" assumption. Many people equate good central vision with healthy eyes. If they can read, drive and watch television without difficulty, they assume everything is fine.
• Infrequent eye exams. Unlike dental check-ups, regular comprehensive eye exams are not a habit for most Australians. Many adults go years or even decades between eye tests.
• Cost and access barriers. For people in regional and remote areas, or those without easy access to an optometrist, routine eye health checks can fall to the bottom of the priority list.
• Lack of awareness. Many Australians simply do not know that glaucoma exists, that it runs in families, or that it can develop without any symptoms at all.

The role of routine eye exams

Because glaucoma rarely announces itself, the condition is most often detected during a routine comprehensive eye examination. Optometrists assess several indicators of eye health during these visits, including intraocular pressure, the appearance of the optic nerve and the integrity of the visual field.

Optometry Australia recommends that adults have a comprehensive eye exam at least every two years, and more frequently for those with known risk factors such as a family history of glaucoma, age over 50, or particular ethnic backgrounds. Yet many Australians do not follow this guidance. A significant proportion of adults only visit an eye care professional when they notice a problem with their vision, which for glaucoma is often too late.

This is where community-level awareness efforts become important. The more people understand that glaucoma can develop without symptoms, the more likely they are to schedule preventive eye exams rather than waiting for trouble.

What 150,000 undiagnosed cases means

The scale of undiagnosed glaucoma in Australia carries real consequences. Each of those 150,000 individuals is at risk of progressive, irreversible vision loss that could have been slowed or managed if identified earlier. Late-stage glaucoma affects independence, mobility, the ability to drive and overall quality of life. It also places a greater burden on the healthcare system, as advanced cases require more intensive and costly management.

From a public health perspective, closing the gap between diagnosed and undiagnosed cases is one of the most impactful things we can do. Early identification allows for early intervention, and early intervention is the single most effective way to preserve vision in people with glaucoma.

Building awareness at the community level

Addressing the undiagnosed glaucoma gap requires more than telling people to visit their optometrist. It requires meeting people where they already are, whether that is in pharmacies, community centres, or online. Educational awareness tools like G-Screen are designed to help people learn about their potential risk factors and understand why a professional eye exam matters, especially if they have never considered glaucoma before.

Learning more about the condition, including who is most at risk and how it progresses, is a valuable first step. You can explore our glaucoma information page for a comprehensive overview.

The goal is simple: fewer people discovering glaucoma too late, and more people taking proactive steps to protect their vision while there is still time to act.