Abstract: An adjustable intrastromal device adapted for implantation in the cornea and formed of a flexible hollow shell composed of a material such as a silicone or urethane polymer, with a chamber that may be filled with a biocompatible material such as saline or gel. Preferably, the device has more than one compartment, each of which is water-tight and distinct from the other compartments. Each compartment contains a predetermined amount of the biocompatible fluid described, and the device is implanted in the cornea in surrounding relation to the optical zone of the cornea. Increased volume displaced by the ring results in greater flattening of the central anterior corneal curvature thus correcting myopia. Preferably, the myopia is slightly overcorrected resulting in more flattening of the cornea than necessary for optimal vision.