Mechanical modifications of soft actuators for the use as a dynamic iris implant

Abstract

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.