Harshit Aggarwal  supervised by Dr. Kavita Vemuri  received his Master of Science – Dual Degree  in Computer Science and Engineering (CSD). Here’s a summary of his research work on Pupillary Light Reflex measurement in myopic children using IR camera embedded VR-HMD device: 

The global rise in pediatric myopia has intensified the need for objective biomarkers to understand the functional retinal changes associated with refractive error. The pupillary light reflex (PLR) serves as a non-invasive window into the health of rods, cones, and intrinsically photosensitive retinal ganglion cells (ipRGCs). However, traditional pupillometry is often constrained by stationary hardware, narrow spectral stimuli, and the challenges of testing pediatric populations. This thesis explores the use of a Virtual Reality Head-Mounted Display (VR-HMD) with integrated infrared eye tracking as a portable, high-precision platform for broad-spectrum chromatic pupillometry. A cohort of 117 children (ages 6–14) was recruited and categorized into emmetropic, low myopic, and high myopic groups. Participants were exposed to an eight-color paradigm (Red, Green, Blue, Yellow, White, Purple, Indigo, and Black) generated on an OLED display, followed by a custom computational pipeline (PuReST algorithm) to extract quantitative metrics. The VR-HMD platform was first validated by reproducing canonical PLR waveforms, demonstrating that it effectively disengages the vergence-accommodation conflict through full-field stimulation. Statistical analysis revealed that myopic children exhibit a significantly greater Maximum Constriction Amplitude (MCA) in response to high-illuminance stimuli (Yellow and White light) compared to emmetropes, suggesting an altered dopaminergic modulation or increased photosensitivity to luminance. Furthermore, myopes demonstrated a significantly faster Maximum Constriction Velocity (MCV) in response to long-wavelength Red light, supporting the hypothesis of an upregulated L-cone pathway adaptation to myopic defocus. A striking “anomalous” response was observed for Indigo light, where participants displayed three distinct phenotypes: constriction, dilation, or no change. A targeted follow-up study (N=43 adults) deconstructed this effect, revealing that the anomaly was driven by a negative luminance contrast relative to the background, creating a perceptual conflict between chromatic constriction and luminance-driven dilation. Finally, exploratory case studies of participants with strabismus, high hyperopia, and amblyopia further demonstrated the system’s sensitivity to diverse neuro-visual pathologies. This research establishes the VR-HMD as a valid scientific instrument for quantitative pupillometry. The findings provide new physiological evidence for functional neuro retinal differences in the myopic eye and position VR-based chromatic pupillometry as a scalable solution for tele-ophthalmology and the identification of predictive biomarkers for myopia progression.

Keywords: Chromatic Pupillometry, Virtual Reality, Myopia, Pediatric Vision, Retinal Photoreceptors, Pupillary Light Reflex.

May 2026