Our technology

We made clinical-grade neurological measurement possible outside clinical settings.

That is the invention. Everything else follows from it.

The Scientific Foundation

A signal that neuroscience has studied for decades.

The Pupillary Light Reflex is one of the most studied physiological signals in neuroscience. When light hits the retina, the pupil constricts automatically — a response regulated by the autonomic nervous system, below the threshold of conscious control. It cannot be suppressed, exaggerated, or faked.

What makes the PLR scientifically valuable is not just that it is involuntary — it is that it is informative. Decades of research have established that PLR parameters change measurably when a neurological condition is affected by fatigue, sleep deprivation, stress, medications, or alcohol. How fast the pupil constricts. How much it constricts. How consistently it recovers. These are not random variations — they are neurologically meaningful signals that reflect the actual condition of the person being measured.

Doctors have long used PLR analysis to evaluate patients in hospitals and specialized settings. It is a standard tool in neurology, critical care, and pharmacological research. The science is not new. The application is.

The Invention

The problem was never the science. It was the hardware — and the know-how. Early attempts to bring PLR measurement outside clinical settings existed, but the devices required were expensive, bulky, and impractical for operational environments. A technology confined to hospitals and specialized practices cannot prevent a workplace accident at the start of a shift.

The question we set out to answer was whether the measurement could be made field-deployable — without sacrificing the accuracy and reliability that made it clinically valuable. The answer was a smartphone. But not simply a smartphone.

Modern smartphones have the camera resolution, processing power, and portability that PLR measurement requires. What they were not designed to do is make accurate biometric measurements. Consumer cameras are optimized for photography — not for the precise, repeatable capture of physiological signals under controlled conditions. Adapting that hardware for clinical-grade measurement required developing the know-how to extract reliable PLR data from a device built for an entirely different purpose — calibrating the capture parameters, processing the video stream with the precision that neurological measurement demands, and ensuring consistency across different device models, eye colors, and age groups.

The enclosure solved the environmental problem. The controlled lighting, fixed distance, and elimination of ambient variability created the conditions the measurement requires. But the engineering challenge was to make a consumer camera perform as a reliable biometric instrument — that is our know-how.

OPTOVERA Testing Device

The result is a measurement that is objective, tamper-resistant, and fully operational in any environment — with or without an internet connection. In a mine. On a loading dock. At the start of a shift.

Patent Protection

The invention is protected. SOBEREYE holds two US patents covering the core of our neurological measurement technology. US Patent 9,888,845 covers the method of using a mobile device — in combination with a controlled enclosure — to perform pupillary light reflex measurement and compare the result against an individual's established baseline. The comparison against a personal baseline is what makes each result meaningful — it is not a population average, it is a deviation from that specific person's own normal. US Patent 10,070,787 extends the protection to cover additional aspects of the measurement methodology and its application to workforce condition assessment. Together, these patents protect the foundational approach that OPTOVERA is built on — the combination of smartphone hardware, controlled lighting, and individualized baseline comparison that makes field-deployable PLR measurement both accurate and operationally viable.

Independent Validation

The approach was validated independently. Independent validation matters because conviction is not evidence. We collaborated with researchers at the University of Naples Federico II to conduct a rigorous empirical evaluation of our smartphone-based pupillometry methodology. The study involved 30 subjects across a range of ages and eye colors — a deliberate design choice to test the methodology against the real variability of a working population rather than a controlled homogeneous sample.

The findings established two things:

• Measurement accuracy — the smartphone approach captured PLR measurements with sufficient accuracy for reliable pupillometry, achieving a mean error smaller than 2 pixels against a manually annotated ground truth across all subjects and conditions.
• Eye safety — the iPhone flash used in the SOBEREYE enclosure setup was tested against ISO 15004-2.2 and ANSI Z80.36 — the international standards for ophthalmic instruments. All measured values were significantly below the defined limits across all iPhone models tested.

The study was published as a peer-reviewed paper at the ICIAP 2017 International Conference on Image Analysis and Processing. Download the paper

From Technology to Product

The technology is the foundation. OPTOVERA is what makes it possible.

SOBEREYE's measurement technology does not exist in a laboratory. It exists at the start of every shift — deployed in safety-critical operations across more than ten countries.

The science was already there. We built the technology to make it matter.

PLR Research summary

• Pickworth [1] [2] [3], Jasinski [4], and Cone [5] have demonstrated a strong effect on pupil diameter and amplitude (both reduced) by all the major opiates including heroin, morphine, and codeine.
• Rowbotham [6] [7] has reported significant increases in pupil diameter for subjects given intravenous and oral cocaine.
• Tennant [8] has reported similar increases for amphetamines. Tennant also describes pupillary changes resulting from marijuana, benzodiazepines (Valium), alcohol, and phencyclidine (PCP).
• Lowenstein [9] and Yoss [10] studied changes in the shape and stability of the pupil light reflex as a person moves from alertness through fatigue to sleep. The findings show that extreme fatigue causes reduced pupil diameter and unstable pupil responses.
• Różanowsky et al. [12] were able to demonstrate correlation and confirm the usefulness of PLR analysis in the assessment of sleep deprivation.
• Pupillary changes also occur in some neurological conditions. Profound pupillary changes are often observed as a result of brain lesions or tumors as well as impending stroke [11].

Bibliography

PLR Research summary [1] H. L. a. P. J. F. Wallace B. Pickworth, Buprenorphine- Induced Pupillary Effects In Human Volunteers, vol. 47, Life Sciences, 1990, pp. 1269-1277. [2] P. W. J. H. a. E. C. Wallace B. Pickworth, Opiate-Induced Pupillary Effects In Humans, vol. Methods And Findings In Experimental Pharmacology, 1989, pp. 759-763. [3] R. V. F. a. E. B. B. Wallace B. Pickworth, "Effects of abused drugs on pupillary size and light reflex," in Drug Abuse Handbook, CRC Press LLC, 1998. [4] P. J. F. A. R. E. J. Donald R. Jasinski, "Sublingual Versus Subcutaneous Buprenorphine in Opiate Abusers," Clinical Pharmacology & Therapeutics, 1989. [5] E. J. Cone, "Testing Human Hair For Drugs Of Abuse. Individual Dose And Time Profiles Of Morphine and Codeine In Plasma, Saliva Urine and Beard Compared to Induced Effects On Pupils And Behavior," Journal Of Analytical Toxicology, no. Jan-Feb, 1990. [6] R. J. A. N. B. M.C. Robotham, "Trazadone-Oral Cocaine Interactions," Archives Of General Psychiatry, vol. 41, pp. 895-899, 1984. [7] W. H. J. M. a. R. J. M.C. Rowbotham, "Cocaine- Calcium Channel Antagonist Interactions," Psychopharmacology, no. 93, pp. 152-154, 1987. [8] F. Tennant, "The Rapid Eye Test To Detect Drug Abuse," Post Graduate Medicine, vol. 84, pp. 108-114, 1988. [9] O. L. a. I. Lowenfeld, "Types Of Central Autonomic Innervation And Fatigue," Archives Of Neurology And Psychiatry, vol. 66, pp. 581-599, 1951. [10] N. M. a. R. H. R. Yoss, "Pupil Size And Spontaneous Pupillary Waves Associated With Alertness, Drowsiness and Sleep," Neurology, vol. 20, pp. 545-554, 1970. [11] P. S. a. J. T. R. Burde, Clinical Decisions In Neuro-Ophthalmology, The C.V. Mosby Company, 1985, pp. 221-245. [12] K. Różanowsky, M. B. A. K., Estimation of operators' fatigue using optical methods for determination of pupil activity, International Journal of Occupational Medicine and Environmental Health, 2015, 28(2):263 – 281.