Intraocular lens
An intraocular lens includes a plurality of lenses with a rear lens portion disposed in a posterior capsule from which an eye lens is extracted and a front lens portion disposed at the front side inside the eye in relation to the rear lens portion, and a support portion of the front lens portion among the lenses has flexibility. Accordingly, when the inside of the user's eye moves, the support portion is bent, and hence the front lens portion moves. When the front lens portion moves so that the gap between the front lens portion and the rear lens portion changes, a focal distance of a lens system including the front lens portion and the rear lens portion changes. Accordingly, it is possible to realize an intraocular lens capable of changing a focal distance in a manner such that a user moves the inside of an eye.
1. An intraocular lens comprising:
a rear lens portion which has a lens function and is adapted to be received in a posterior capsule inside an eye from which an eye lens is extracted while at least the posterior capsule is left; and
a front lens portion which has a lens function and is adapted to be disposed at the front side inside the eye in relation to the rear lens portion such that the front lens portion is spaced apart from the rear lens portion,
wherein the front lens portion includes
a first lens which is adapted to be disposed at a position facing a lens surface of a second lens as a lens of the rear lens portion, and
a support portion which is adapted to extend from a limbus of the first lens to a position of a part of a region from an iris to a ciliary body inside the eye, supports the first lens, and has flexibility, and
wherein the support portion includes
an extension portion which is formed in a shape extending toward a lateral side of the first lens and supports the first lens while a portion farthest from the center of the first lens in the shape is adapted to come into contact with the inside of a ciliary sulcus of the eye, and
a sub-extension portion which is branched from a side surface of the extension portion, is adapted to extend toward the rear side inside the eye, and is adapted to come into contact with a surface of the ciliary body so that a force of pressing the first lens toward the front side inside the eye is transmitted when the sub-extension portion is pressed by the ciliary body.
2. The intraocular lens according to claim 1 ,
wherein one of the first lens and the second lens is a convex lens and the other thereof is a concave lens.
3. The intraocular lens according to claim 1 ,
wherein the support portion has a bent shape in which the support portion is adapted to bend in response to the movement of the region from the iris to the ciliary body while a front end of the support portion comes into contact with a position of a part of the region from the iris to the ciliary body inside the eye so that the first lens is movable inside the eye in the front and rear direction.
4. The intraocular lens according to claim 1 ,
wherein the support portion includes a nipping portion which is formed in a shape extending toward the lateral side of the first lens disposed at the rear section and is adapted to nip a part of the rear section side of the iris of the eye so as to support the first lens.
5. The intraocular lens according to claim 4 ,
wherein the shape of the nipping portion is adapted to be a shape in which a portion nipping the iris in the nipping portion is located at the front side inside the eye in relation to the first lens.
6. The intraocular lens according to claim 1 ,
wherein the extension portion has a bent shape, and the bent shape is a shape in which the first lens is movable inside the eye in the front and rear direction in response to the movement of the ciliary sulcus while a portion farthest from the center of the first lens in the extension portion is adapted to come into contact with the inside of the ciliary sulcus of the eye.
7. The intraocular lens according to claim 1 ,
wherein the extension portion has flexibility and has a size in which at least a part of the extension portion is bent while a portion farthest from the center of the first lens in the extension portion is adapted to come into contact with the inside of the ciliary sulcus of the eye.
8. The intraocular lens according to claim 1 ,
wherein the extension portion includes a plurality of leg portions which are adapted to extend from a plurality of positions of the limbus of the first lens in the circumferential direction in a direction moving away from the center of the first lens due to the leg shape.
9. The intraocular lens according to claim 8 ,
wherein a front end of the leg portion is adapted to come into contact with at least a part of a deep portion of the ciliary sulcus while being inserted into the ciliary sulcus of the eye.
10. The intraocular lens according to claim 8 ,
wherein the leg portion includes a bent portion which is bent at a position between an end close to the first lens and an end far from the first lens in the leg shape, and
wherein the leg portion has a shape in which the end close to the first lens in the leg portion is adapted to be located at the front side of the eye in relation to the bent portion and the end far from the first lens in the leg portion is adapted to be located at the front side of the eye in relation to the bent portion so that the first lens is pressed toward the front side inside the eye when the ciliary sulcus presses the leg portion while the first lens is disposed at the rear section of the eye.
11. The intraocular lens according to claim 9 ,
wherein the leg portion includes a bent portion which is bent at a position between an end close to the first lens and an end far from the first lens in the leg shape, and
wherein the leg portion has a shape in which the end close to the first lens in the leg portion is adapted to be located at the front side of the eye in relation to the bent portion and the end far from the first lens in the leg portion is adapted to be located at the front side of the eye in relation to the bent portion so that the first lens is pressed toward the front side inside the eye when the ciliary sulcus presses the leg portion while the first lens is disposed at the rear section of the eye.
12. The intraocular lens according to claim 1 ,
wherein the extension portion includes an annular ring portion which is inserted into the ciliary sulcus in the circumferential direction.
13. The intraocular lens according to claim 1 ,
wherein a portion adapted to come into contact with the inside of the ciliary sulcus in the extension portion is provided with a concave portion or a convex portion which is fitted to an uneven portion inside the ciliary sulcus.
14. The intraocular lens according to claim 1 , wherein the rear lens portion includes the second lens having a lens function and a loop portion.
15. The intraocular lens according to claim 14 , further comprising a pair of loop portions formed at a limbus of the second lens at the opposite side in the optical axis.