The lenticular capsule-expanding device (1) is set inside a lens capsule in which the anterior capsule has been sectioned in cataract surgery, etc. and is equipped with: a circular front support section (11), which is provided in a form that connects the inner surface of the anterior capsule (Sf) a circular rear support section (12) that is provided on the rear side of the front support section (11) in a form that contacts the inner surface of the posterior capsule (Sb) while facing the front support section (11) and a connecting section (13) for connecting the rim of the front support section (11) to the rim of the posterior support section (12) in a form that has a biasing force in the direction that separates the front section (11) from the rear support section (12). As a result of the biasing force of the connecting section (13), the front support section (11) presses the inner surface of the anterior capsule (Sf) and the rear support section (12) presses the inner surface of the posterior capsule (Sb).
