ACCOMMODATIVE INTRA-OCULAR LENS

摘要

An accommodative intra-ocular lens 10 deformable between the unaccommodating and accommodating configurations respectively upon the relaxation and contraction of the ciliary muscle 28. The lens includes an anterior portion and a posterior portion 32, 34. The lens anterior and posterior portions 32, 34 are substantially sealingly joined together about their respective anterior and posterior portion peripheral edges 48, 54 and define a lens internal volume filled with a substantially incompressible lens internal fluid 58. The lens internal fluid defines a variable internal fluid pressure exerted on the anterior and posterior portion inner surfaces. The lens 10 is configured such that radius of curvature of both the central and peripheral sections 44, 46 of the lens anterior portion will decrease upon an increase in internal fluid pressure and increase upon a decrease in internal fluid pressure. In a first embodiment, the main actuating effect is the increase in vitreous humor pressure caused by the contraction of the ciliary muscle 28 and transmitted to the internal fluid 58 by the lens posterior portion 34. In a second embodiment, the main actuating effect is the decrease in circumlenticular space caused by the contraction of the ciliary muscle 28 that is converted by haptics 82 into a movement of the anterior and posterior lens portions 32, 34 towards each other. In both cases the contraction of the ciliary muscle 28 eventually causes an increase in internal fluid pressure that deforms the lens anterior portion 32 towards the accommodated configuration. In both cases, the configuration of the lens anterior portion is such that refractive aberrations are minimized substantially throughout the range of accommodation.