Fischell Institute Engineers Develop Advanced Eye Pressure Measurement Device

Robert E. Fischell Institute for Biomedical Devices engineers have developed a device that measures intraocular pressure (IOP) without the need for an air-puff test by using a high-speed camera to look at how an eye flexes during a blink.

The device, called FireFly, was developed through a collaboration between Fischell Institute Fellow and Fischell Department of Bioengineering Professor Giuliano Scarcelli, Amal Isaiah, former Fischell Fellow and University of Maryland School of Medicine Professor of Otorhinolaryngology - Head & Neck Surgery, and the Fischell Institute Foundry.

IOP is an important measurement for glaucoma screening and monitoring. Glaucoma is the leading cause of irreversible blindness worldwide, and it is largely preventable if caught early, according to Scarcelli and Isaiah. Eye pressure is the single most important modifiable risk factor for glaucoma, yet half of the people with glaucoma do not know they have it.

“The bottleneck is measurement: today, checking eye pressure requires a clinic visit, a trained operator, and often numbing drops,” said Isaiah. “That means we get one or two snapshots a year of a disease that fluctuates hour to hour. If IOP measurement becomes as easy as checking your heart rate on a smartwatch, we shift from episodic screening to continuous monitoring, catching pressure spikes when they happen, personalizing treatment, and reaching the millions of people who never make it into an ophthalmologist's chair.”

The eye is constantly giving us information for free, Isaiah added. Every blink deforms the cornea in a way that encodes its biomechanical state, including pressure. The team’s early work showed that these blink dynamics can be captured without ever touching the eye, with no puff of air, probe or anesthetic.

In 2021, Fischell Institute Chief Engineer John Rzasa and Senior Engineer Kevin Aroom built a tabletop FireFly system for Scarcelli and Isaiah. Following encouraging results from the initial system, Rzasa and Aroom redesigned and miniaturized the technology into a more accessible, VR-style headset.

“This is a clear example of the Foundry’s ability to take an idea from a clinician and transform it into a functional prototype for further investigation and development,” said Aroom. “This specific project leveraged skill in wearable design, optics, programming and automated machine vision algorithms.”

The tabletop system required training to align with a user’s eye. The new headset simplifies that process and allows for faster data collection, helping the team optimize its algorithms.

Published July 27, 2026