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Aniridia is a condition characterized by defects or absence of the iris. Since the eyes are a central point of attention in the human face, these deformities are often covered with cosmetic implants. However, patients suffer from the static pupil diameter of these implants, resulting in high light sensitivity or inadequate night vision. Therefore, we present a functional iris implant based on dielectric elastomer actuators. These electric drives are characterized by a silent and continuous adaptation as well as a small construction volume and a low heat emission. Since they normally exhibit in-plane uniaxial motion, this displacement must be focused to operate similarly to the iris sphincter. Therefore, we investigated possible mechanical modifications of the setups to generate a directional motion. The results of the study are presented and discussed.Clinical Relevance-The proposed system design enables the functional treatment of aniridia and other accidental iris defects. In addition, the system serves as a basis for later developments of e.g. functional lenses that allow focus adjustment.

Apertures are used in optical systems to limit the luminous flux. In the human eye the iris serves this purpose but can be damaged requiring an implant, which to date is static, limiting the optical performance. The authors thus report the development of a prototype demonstrating the feasibility of a flexible dynamic iris implant manufactured with an automated manufacturing technique. The presented actuators are printed via aerosol jet printing allowing a high reliability in produced electrode quality. Through optimization of the actuator design for maximum contraction they demonstrate a pupil area reduction of 13.40% or 6.94% reduction of pupil diameter, respectively. Thereby the prototype demonstrates an illuminance reduction of 18.25% in the central visual axis. Furthermore, they present a first iteration of a bionic closed-loop control mimicking the human iris reflex thus laying the foundation for a self-controlled iris implant.

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