Visual Function, Eye Movements, and Vision Loss

Glaucoma is one of the leading causes of irreversible blindness worldwide. Effective management depends on detecting functional changes early and understanding how visual deficits affect everyday behavior. My research investigates how eye movements and reaction times can be used to characterize visual function and provide new insights into the relationship between retinal structure, visual processing, and behavior. 

A central goal of this work is to develop objective and behavior-based approaches for measuring visual function. Unlike traditional clinical tests that primarily assess whether a stimulus is detected, eye-movement-based methods capture how rapidly sensory information is transformed into action. This provides a complementary perspective on visual function and may reveal aspects of visual processing that are not fully captured by conventional assessments. 

Current research spans three closely connected areas:

Measuring Visual Function Through Natural Behavior

We develop and evaluate eye-movement-based methods that use saccadic reaction times and gaze behavior as quantitative measures of visual function. By studying how visual information is transformed into actions, we aim to establish sensitive behavioral markers of visual performance and sensory impairment. 

Linking Structure and Function

Visual impairment ultimately arises from changes in the nervous system. By combining behavioral measurements with retinal imaging, we investigate how changes in retinal structure relate to visual performance. Understanding this relationship is essential for improving the assessment and interpretation of sensory deficits. 

Binocular Vision and Functional Adaptation

Humans normally interact with the world using both eyes simultaneously, yet most clinical assessments remain monocular. We study how visual information from the two eyes is combined and how binocular processing is affected when visual function differs between eyes. These studies contribute to understanding how people adapt to sensory impairment and maintain functional behavior in everyday life. 

Team and Collaborations

This research is conducted in close collaboration with clinical and academic partners.

The programme includes the doctoral work of Ashwini V.R. Chanakya, whose research focused on eye movement perimetry, reaction-time analysis, structure-function relationships, and binocular visual processing in glaucoma.

Current work by Suzanna M. L. Janssens focuses on developing experimental methods that enable the investigation of visual-field deficits and sensory impairments under highly controlled laboratory conditions. Using reversible retinal desensitisation, her research establishes behavioral models of visual impairment in healthy participants, providing an efficient platform for developing and evaluating new approaches to visual-function assessment and eye-movement-based diagnostics.

An important international collaboration is with Dr. Ronnie George and colleagues at the Medical Research Foundation, Sankara Nethralaya in Chennai, India, combining expertise in glaucoma, clinical ophthalmology, and visual neuroscience. 

The research is further strengthened through collaborations with clinicians (Dr. Gijs Thepass, Oogziekenhuis Rotterdam), engineers (Dr. Daan Pool, TU Delft), industry partners (PurpleGaze, OptiekTOM), and a public-private initiative public-private initiative (SMART-EMP) aimed at translating fundamental insights into practical tools for assessing visual function. 

Stichting Lijf en Leven (74_P.Bremen EMC) & EMC Starting Grant & LSH PPS WorkTech (PPS-WT25-02)