WP 2.2: Age-dependent neural transfer function

Age-related structural and physiological changes in the human visual system lead to impairment of key visual functions. While age-related optical factors underlying this decline have been studied extensively, the neural contribution remains less well understood. This work package therefore measures the neural component of contrast sensitivity by bypassing the optics of the eye and analysing changes with age. The goal is to improve personalised optical correction strategies, provide insights into retinal and neural diseases, and support earlier diagnosis of age-related neurological conditions.

Within this project, direct measurement of the neural component of contrast sensitivity is achieved with a spatial light modulator interferometric setup. The instrument presents finely controlled interference patterns directly on the retina, and perception is measured using a two‑interval forced‑choice procedure to derive neural contrast sensitivity free from optical aberrations. We recently completed a large foveal dataset in healthy adults (93 individuals from 20 to 80 years of age) and found a clear age‑related decline, with the strongest reduction in the 70+ age group. Ongoing analyses test whether this decline reflects neural cell loss or long‑term adaptation to increased lens opacity. Next steps extend measurements to the peripheral visual field and relate neural changes to clinically relevant outcomes.