A deformable mirror with variable curvature including: a plate having a reflective face and opposite hidden face and whose shape has a center (C) and radiuses (r), and at least one actuator intended to exert a force on the hidden face in order to deform the plate. The plate comprises a plurality of primary and secondary portions. The secondary portions being interposed between the primary portions, each of the primary portions extending locally substantially along and on either side of a respective radius (r′) among said radiuses (r), and having a stiffness different from the adjacent secondary portions. The deformable mirror is intended to the introduction or the correction of an optical aberration in a light beam.