Correction of eye refractive errors like presbyopia, hyperopia, myopia,
and astigmatism using either pre-tensioned or transcutaneously energized
artificial muscle implants to change the axial length and anterior
curvatures of the eye globe by bringing the retina/macula region to
coincide with the focal point. The implants are scleral constrictor
bands, segments or ribs for inducing accommodation of a few diopters, to
correct refractive errors on demand or automatically. The implant
comprises an active sphinctering band encircling the sclera, implanted
under the conjunctiva and under the extraocular muscles to uniformly
constrict the eye globe, to induce active temporary myopia (hyperopia) by
increasing(decreasing) the length and curvature of the globe. Multiple
and specially designed constrictor bands enable surgeons to correct
astigmatism. The artificial muscles comprise materials such as composite
magnetic shape memory (MSM), heat shrink, shape memory alloy-silicone
rubber, electroactive ionic polymeric artificial muscles or
etectrochemically contractile ionic polymers bands.