Kowa Company Limited

Haruo Ishikawa

Takayoshi Suzuki

Shuji Abe

Kimiya Shimizu

Norio Shimizu

Yasuhiro Hishinuma

Akemi Taniguchi

Kotaro Mitsumoto

A multifocal diffractive lens is provided which achieves efficient use of light. The multifocal diffractive lensincludes a diffraction grating. Negative-order light Lproduces a focal point ffor far vision and 0-order light Lproduces a focal point fnearer to that for far vision. The number of focal points is two or more. The focal position fc for far vision in polychromatic performance evaluation is located nearer to the multifocal diffractive lens than the focal position fs for far vision in monochromatic performance evaluation.

Multifocal diffractive lens

There is provided a toric intraocular lens which improves the visibility of a toric axis. The toric intraocular lens is a toric intraocular lens including a lens body provided with an astigmatic axis. A mark indicating the astigmatic axis is formed at an optical surface of an outer rim portion of the lens body, and a length in a radial direction of the lens body and a length in a circumferential direction of the lens body of external dimensions of the mark are different from each other in top view of the optical surface.

Toric intraocular lens, intraocular lens insertion tool, and method for producing toric intraocular lens

To realize a toric ophthalmic lens including an edge that makes it possible to design a lens contributing to secondary cataract prevention without deteriorating a degree of freedom of lens design. The toric ophthalmic lens is a toric ophthalmic lens in which, in a top view of an optical portion, a substantially flat portion having a substantially fixed edge thickness of the optical portion is provided to overlap a steep meridian of a toric surface of the optical portion.

Toric ophthalmic lens

A toric intraocular lens includes a lens body, support portions, and connecting portions for connecting the lens body and the support portions. The lens is housed in an insertion apparatus that includes a tubular apparatus body having an insertion tube for the lens and a plunger for moving the lens. Each of the connecting portions is arranged at a position where the connecting portions face each other across a center of an optical axis of the lens body. One end of the flat meridian of the lens body is located at a position opposite to a position, with respect to an axis that passes through the center and connects the connecting portions, at which the plunger contacts the lens body. An angle between the flat meridian and an axis along which the lens is pushed by the plunger is larger than 0&#xb0; and equal to or smaller than 90&#xb0;.

Toric intraocular lens and intraocular lens insertion apparatus

A tonic ophthalmic lens is described in which refractivity of the lens differs between a first direction on a plane perpendicular to an optical axis of the lens and a second direction which differs from the first direction on the plane. In addition, refractivity difference which is the difference between the refractivity in the first direction and the refractivity in the second direction varies depending on a position of the lens in a radial direction.

Provided is a technique which, in the design of intraocular lenses, simplifies design work and makes it possible for aberration of the entire eyeball to more precisely match a target value when the designed intraocular lens is inserted into a patient's eye. This intraocular lens design method involves deriving an intraocular lens aberration target value from the aberration of the cornea and anterior chamber and a set value of the total eyeball aberration (S), and determining an intraocular lens shape such that the at least the aberration of the intraocular lens coincides with the target value (S-S). The intraocular lens aberration is set to an intraocular lens aberration for which prescribed convergent light is incident to the intraocular lens (S).

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Nagoya, Japan

Haruo Ishikawa