A Method and Apparatus for Measurement of Relative Afferent Pupillary Defect for Assessment of Neurological Disorders

Case ID:


The field of Ophthalmology, responsible for diagnosing and treating eye and brain disorders, has for years utilized the relative afferent pupillary defect (RAPD) test to identify neurological damages in the visual pathways. The traditional "swinging flashlight" test evaluates the pupil's response to light stimulus to detect differences between both eyes. This test, though vital, relies heavily on a clinician's keen observation. Given the complexity of the visual pathways, accurate detection and interpretation are critical but challenging.


University of Nevada, Reno's technology utilizes a Head-Mounted Display (HMD), akin to Virtual Reality (VR) headsets, to enhance the precision and efficiency of Relative Afferent Pupillary Defect (RAPD) testing. By leveraging the HMD's advanced visualization, processing, and eye-tracking capabilities, it provides a comprehensive, modular approach for assessing RAPD in patients. This novel method allows for detailed evaluation of pupillary responses to light stimuli in real-time. In addition to its precision, the HMD offers flexibility, enabling various medical practitioners or even the patients themselves to administer the test, thereby revolutionizing the approach to detecting potential neurological disorders.


  • Real-time Feedback: Ability to recognize abnormal test results instantaneously and adapt the test accordingly. Allow for serious medical conditions to be identified early.
  • Enhanced Accuracy: With computer-aided detection, the chances of human error diminish.
  • Modularity: Can be operated by various medical practitioners, or even by the patient, enhancing its utility.
  • Standardized Testing Environment: The controlled visual environment ensures consistent testing conditions for every patient.
  • Stress Reduction: Immersive VR can simulate natural settings, potentially reducing anxiety during the test.


  • Medical Diagnostics: Immediate use in ophthalmological clinics for detecting RAPD.
  • Emergency Rooms: Quick assessment tool for neurological damage after traumatic incidents.
  • Research: Enhanced tool for studying neurological deficits in controlled environments.
  • Home Testing: Potential for self-administered tests with telemedical guidance.

Intellectual Property

Patent WO 2022/109546

Patent Information:
For Information, Contact:
Ray Siripirom
Senior Licensing Associate
University of Nevada, Reno
Alireza Tavakkoli
Stewart Zuckerbrod