Oculomotor behavior of children with amblyopia during naturalistic tasks

Amblyopia occurs in 3 – 5% of the population and is defined as a unilateral or bilateral loss of vision resulting from abnormal visual stimulation during the early years of visual development. In clinics, the diagnosis of amblyopia largely relies on a decreased monocular or binocular visual acuity, the absence of any pathology that would explain the visual deficit, and the presence of an amblyogenic factor (usually strabismus or anisometropia). However, several other visuospatial functions such as contrast sensitivity, stereopsis or visual processing are also affected in amblyopia. Several studies have also reported oculomotor deficits in the amblyopic and fellow eyes, such as longer saccadic latencies and reduced saccadic amplitudes, low pursuit gain, or fixation instability. Usually, these studies are done in very controlled laboratory conditions, presenting visual stimuli on a computer screen and recording eye movements with an eye-tracker. Although these findings are relevant in the context of basic research on the neural mechanisms of amblyopia, the consequences of these oculomotor deficits in daily life are still undetermined. In this work, a protocol to measure eye movements of children with amblyopia with a portable eye-tracker while they do naturalistic tasks which require a combination of visuospatial abilities will be validated and implemented. Their oculomotor behavior will be compared to that of typically developing children to determine how amblyopia affects the performance in daily life activities. This work is part of a bigger project that the research group VISPEC (Visual Optics and Spectral Imaging Group) from the CD6 (Centre for Sensors, Instruments and Systems Development) is carrying out at the moment.