Eye tracking: your eyes know more than you think

What if simple eye tracking could detect a neurological disease years before its first symptoms, reveal a vision problem without a traditional examination, or even help a child get a diagnosis as early as primary school? It's no longer science fiction. Eye-tracking is reaching a crucial milestone , driven by artificial intelligence and the rise of smart glasses. A look back at a discreet but increasingly powerful technology.

Eye tracking: what exactly are we talking about?

Eye tracking refers to all the techniques used to record and analyze eye movements. Speed, fixation time, saccades, pupil dilation: all these data, combined, reveal much more about our brain, our health, and our attention than we realize.

The origins of this discipline date back to the late 19th century, when the French ophthalmologist Louis Émile Javal observed that reading is not achieved through a smooth gliding of the gaze, but through a succession of rapid jumps—the famous saccades —interspersed with pauses. These observations paved the way for decades of research on eye movements, culminating in the advent of computers, which provided eye-tracking with its first digital tools for precise measurement.

Today, eye trackers use low-dose infrared light to track pupil movement, frame by frame.

Eye tracking: what your eyes reveal about your health

This is the field of application that is currently experiencing the most spectacular advances. Long confined to research laboratories, medical ocular tracking is gradually establishing itself as a reference diagnostic tool.

Neurodegenerative diseases in the crosshairs

Eye movement analysis can detect cognitive disorders up to ten years before the onset of the first clinical signs. Parkinson's, Alzheimer's, multiple sclerosis: abnormal saccade or fixation patterns constitute valuable early markers.

Screening for neurodevelopmental disorders in children

In December 2024, SuriCog 's PreTRACK-TND project won the Marcel Dassault Prize for Innovation in Mental Illness. Its aim is to screen for neurodevelopmental disorders (autism, ADHD, learning disabilities, etc.) in elementary school through gaze analysis. In France, these disorders affect 16% of children, but the average wait for an initial diagnosis exceeds 446 days. Following a pilot study with 170 first-grade students in Alsace, a nationwide rollout is planned between 2027 and 2030.

Detecting visual disturbances… without an eye exam

This is perhaps the most unexpected development, and it directly concerns the optical industry. Researchers at the Nara Institute of Science and Technology (Japan) have developed a system called "Mind Your Vision," capable of passively detecting refractive errors—that is, without the patient undergoing any conventional examination.

The principle is based on a simple observation: a person with uncorrected vision develops specific micro-eye behaviors when faced with a blurry image. Their brain compensates by ordering saccades or fixations that the eye of a well-corrected person does not perform. By combining electro-oculography (measuring electrical activity around the eye, which can be integrated into a smart frame) and traditional eye-tracking, the system achieves 96.2% accuracy for a person already familiar to the AI. After a very short learning phase of a few seconds, this accuracy remains at 78.5% for a new user—a result that is still imperfect, but promising.

The ultimate goal: to integrate this system into everyday devices — screens, VR headsets, smart glasses — to silently alert the user when their eyesight is declining, before they even realize it!

Beyond health: a tool with a thousand faces

In reality, eye-tracking technology is not limited to the medical field… It now permeates many sectors that we sometimes experience without our knowledge:

• In high-level sport , saccade analysis provides information on an athlete's level of concentration and can guide training programs.
• UX and marketing : for a long time, website and advertising designers have analyzed eye-catching areas to optimize their visuals. Tools like the Tobii platform allow this type of analysis in real time.
• Automotive : In 2023, 34% of new vehicles tested already incorporated an eye-tracking system to detect driver fatigue or inattention.
• Accessibility : For people with amyotrophic lateral sclerosis (ALS) or other paralysis, eye-tracking allows them to control a computer by looking only — a major step forward for their independence.

The issue of personal data: a challenge that remains relevant today.

While the applications of eye tracking are exciting, they raise ethical questions that have persisted since the initial warnings. Gaze patterns are biometric: they reveal not only a person's identity, but also their health, interests, and cognitive abilities.

As this technology becomes integrated into consumer devices—iris-recognition smartphones, AR/VR headsets, and future smart glasses—the issue of consent and data control becomes paramount. In Europe, the GDPR already regulates this data as sensitive information, but the rapid evolution of its uses will continue to raise questions for regulators and citizens alike.

A booming market

The global market for eye-tracking systems was valued at $1.11 billion in 2024 and is expected to reach $6.60 billion by 2034 , with an annual growth rate of 19.5%. Healthcare alone accounts for 34% of global demand. This trajectory illustrates, with supporting figures, that eye-tracking is no longer a niche technology reserved for laboratories—it is a fully-fledged industry, increasingly present in our daily lives.