Glaucoma is a group of conditions that damage the optic nerve, usually linked to elevated pressure inside the eye. What makes it particularly dangerous is how it progresses: peripheral vision is typically lost first, and slowly enough that the brain compensates without the person noticing — until central vision is affected, by which point the damage cannot be reversed.
Why there are usually no early symptoms
Unlike cataracts, which gradually blur vision in a way that's noticeable, glaucoma tends to erode vision from the outer edges inward. Because both eyes rarely progress at exactly the same rate, the stronger eye often compensates for the weaker one, masking the loss until it's substantial. This is why glaucoma is frequently only caught during a routine eye exam, not because the patient noticed anything wrong.
Who is at higher risk
- Anyone over the age of 40, with risk increasing with age
- A family history of glaucoma
- Diabetes or high blood pressure
- High myopia (nearsightedness)
- Previous eye injury or long-term steroid use
Having one or more of these factors doesn't mean glaucoma is inevitable, but it does mean more frequent screening is worthwhile, even without any symptoms.
How glaucoma is diagnosed
Diagnosis combines several tests rather than relying on any single measurement: intraocular pressure checks, HFA-Perimetry visual field testing to map peripheral vision, pachymetry to measure corneal thickness, and imaging of the optic nerve. Together, these tests can detect early, subtle nerve damage well before it would be noticeable to the patient.
Vision lost to glaucoma cannot be restored — but with early diagnosis, further loss can almost always be prevented or significantly slowed.
Treatment focuses on prevention, not restoration
Because existing damage is permanent, glaucoma treatment is aimed entirely at protecting what vision remains. Depending on severity, this can range from daily pressure-lowering eye drops to Yag laser procedures or surgical intervention, alongside regular monitoring to track whether the current treatment is holding pressure steady.
The takeaway
Because glaucoma rarely announces itself, the only reliable way to catch it early is routine screening — particularly for anyone over 40 or with risk factors above. A comprehensive eye exam that includes pressure testing and a look at the optic nerve is a small step that can prevent an otherwise irreversible loss of vision.