See it before it's lost: how virtual reality is changing visual-field diagnostics

Glaucoma goes unnoticed for years. The brain compensates — until it can't. Early detection depends on a single examination that today is done with an expensive, slow, and rarely available device. At the Institute of Advanced Studies we are working to change that.

Glaucoma goes unnoticed by the patient for years. The brain compensates for the loss — while it still can. Early detection depends on a single examination that today is done with an expensive, slow, and scarce device. At the Institute of Advanced Studies we are working to change that.

Institute of Advanced Studies · published April 2026

The silent loss of sight

Glaucoma is the second leading cause of irreversible blindness worldwide. The World Health Organization estimates that by 2040 more than 110 million people will be affected. Its insidious nature is in this: the patient does not notice it for years. Eye pressure rises slowly, the optic nerve gradually disappears, peripheral vision recedes step by step. Until one day the patient notices that the world looks like a tunnel — and the tunnel keeps narrowing.

The brain is remarkable in that it fills in missing data. If a defect appears in the visual field, the brain seals it — fills it with what the other eye sees, or constructs it from prior experience. Because of this, patients often realise the loss only when thirty or more percent of the visual field is gone forever. Glaucoma cannot be cured — we can only slow its further progression. That is why early detection is everything.

Perimetry — measuring the visual field

How does a doctor determine whether a patient really sees in every part of their visual field? They must test it point by point. This test is called perimetry. In practice it looks like this: the patient looks into a device shaped like a half dome, fixates on a central point, and presses a button whenever they detect a flash of light somewhere in the periphery. The test takes six to fifteen minutes per eye.

The classical clinical perimeter has been used for almost forty years. It is precise and standardised — but it has three fundamental weaknesses. First, it is expensive: one unit costs thirty to forty thousand euros. Many optometric and primary ophthalmology practices cannot afford it, so they refer patients to a separate examination at a hospital — weeks or often months later. Second, it requires a fixed position of the patient in a darkened room, is non-mobile — you cannot take it into the field, into a senior care facility or to a patient’s home. And third, it is exhausting: during a long test, fatigue makes patients invent answers towards the end.

The result? Perimetry — despite its key role — is the weakest link in glaucoma care. Audits in both Europe and the US show that fewer than forty percent of patients adhere to the recommended testing cadence (two tests a year for at-risk, four for affected). Many patients simply never come back after the first referral.

Enter virtual reality

At the Institute of Advanced Studies we are working to change this. Our answer is technologically elegant: perimetry built on commonly available virtual-reality headsets with integrated eye tracking. The principle remains the same — the patient observes light stimuli in the visual field and reacts to them. The way they do it, however, changes from the ground up.