Glaucoma: Why It Has No Symptoms and How It Is Found Early

Glaucoma is one of the leading causes of irreversible blindness, and its defining feature is that you will not notice it happening.

There is no pain, no blur, and no obvious warning. The damage begins in your peripheral vision, and the brain fills in the missing area so convincingly that most people are unaware until a substantial proportion of the optic nerve has already been lost. That loss cannot be recovered.

This is why glaucoma is found at routine eye examinations rather than because someone booked one.

What is actually happening

Glaucoma is a group of conditions in which the optic nerve is progressively damaged. The nerve carries the signal from your eye to your brain, and once its fibres die they do not regenerate.

Raised pressure inside the eye is the main modifiable risk factor and the thing most treatment targets. It is not the whole story, which matters more than it sounds, because a substantial number of people develop glaucoma at pressures that read as entirely normal.

The main types

Primary open angle glaucoma is the most common in Australia. Drainage of fluid from the eye becomes gradually less efficient, pressure rises slowly, and damage accumulates over years without symptoms.

Angle closure glaucoma occurs when the drainage angle becomes physically blocked. It can develop slowly, but an acute attack is a medical emergency, presenting with severe eye pain, redness, blurred vision, haloes around lights, and often nausea and vomiting. That combination needs same day attention rather than a routine appointment.

Normal tension glaucoma produces characteristic optic nerve damage despite pressures within the normal range. It is the reason a pressure reading alone is not a glaucoma test.

Secondary glaucoma follows something else, such as injury, inflammation, advanced diabetic eye disease, or prolonged steroid use.

Who is at higher risk

Risk rises considerably with age, particularly beyond fifty. A first degree relative with glaucoma raises your own risk severalfold, which makes family history one of the most useful things you can tell us.

Other contributors include high short sightedness, previous eye injury, long term steroid use, and certain ethnic backgrounds where particular types are more prevalent.

If a parent or sibling has glaucoma, you should be having regular examinations regardless of how well you see.

How it is detected

No single test diagnoses glaucoma. It is a picture built from several.

We measure intraocular pressure, examine the optic nerve directly, assess the drainage angle, and test the visual field to map any functional loss.

Alongside these, OCT imaging measures the thickness of the nerve fibre layer around the optic nerve in microns. This matters because structural thinning is measurable before any loss shows up on a visual field test, and because repeat scans over years let us distinguish genuine progression from normal variation. Detecting change earlier is the entire game in a disease where nothing lost comes back.

How it is managed

Treatment aims to lower pressure sufficiently to halt or slow further damage. It does not restore vision already lost, which is why early detection matters so much.

Eye drops are usually the first line, and they work either by reducing fluid production or improving outflow. In Australia, therapeutically endorsed optometrists can prescribe topical glaucoma medications, typically working alongside an ophthalmologist depending on the type and severity. Laser treatment and surgery are options where drops are insufficient or not tolerated.

The most common reason treatment fails is not the medication. It is that drops are used inconsistently, because the condition produces no symptoms to remind anyone. Glaucoma treatment is lifelong and largely invisible in its benefits, which makes routine an unglamorous but genuinely important part of it.

Where to from here

The people who do best with glaucoma are the ones who were examined before they had any reason to be.

At Noranda Optometrist, glaucoma assessment including OCT imaging of the optic nerve is part of how we examine adults, particularly those over fifty or with a family history. If you have a parent or sibling with glaucoma and have not had your eyes examined recently, that is worth booking.