A groundbreaking study published in Scientific Reports presents a novel, non-invasive method of measuring the electrical activity of the ciliary muscle during accommodation in people with normal vision. The research was conducted in close collaboration between the Institute for Ophthalmic Research, Centre for Opthalmology, University of Tübingen and Institute for Microsystems Technology (iMST), Furtwangen University.

Using a custom-designed scleral contact lens electrode, the team recorded biopotentials in the millivolt range while participants focused alternately on near and distant targets. These signals were recorded simultaneously with measurements of the eye's refractive power, which were taken using an infrared photorefractor. This enabled the researchers to correlate muscle activity precisely with the refractive state of the eye's crystalline lens.

To ensure measurement accuracy, the team also controlled for potential confounders, such as squinting and eye movements. The team's findings provide valuable insights into the biomechanics of accommodation and could contribute to the development of intelligent, self-adjusting visual aids for age-related long-sightedness.

This study is part of the larger interdisciplinary project "Maintaining Sharp Vision Even in Old Age" of the Applied Vision Research Group at the Institute for Ophthalmology, University of Tuebingen, funded by the Carl Zeiss-Stiftung as part of its program "Breakthroughs at Universities 2020: Intelligent Solutions for an Ageing Society".
 

Here is the link to the original publication:
Non-invasive measuring of biopotentials of the ciliary muscle during accommodation in emmetropes
Schumayer, S., Sigdel, B., Jarboui, M.A. et al. Non-invasive measuring of biopotentials of the ciliary muscle during accommodation in emmetropes. Sci Rep 15, 19389 (2025). https://doi.org/10.1038/s41598-025-04165-3
https://www.nature.com/articles/s41598-025-04165-3