A one-piece intraocular lens is used for a cataract treatment and is configured to be inserted into a capsule of an eye of a patient from which a lens of the eye has been removed. Adhesion of the intraocular lens to the inner surface of the capsule is realized more advantageously by viscosity imparted to the intraocular lens, and the intraocular lens is deployed more positively after it is inserted into the capsule and secured therein while being positioned at a specified location. The intraocular lens has an optical portion (12) and supporting portions that are formed integrally with a viscous material. Each of the supporting portions is provided with a widened part at a basal end thereof, and has a rough surface portion at the basal end.
