Optics: eye examining – vision testing and correcting – Spectacles and eyeglasses – Ophthalmic lenses or blanks
Patent
1989-03-17
1991-12-17
Sugarman, Scott J.
Optics: eye examining, vision testing and correcting
Spectacles and eyeglasses
Ophthalmic lenses or blanks
351159, 351161, 351164, 351171, 623 6, 359494, 359495, G02C 706, G02C 704, G02B 530, A61F 216
Patent
active
050730215
ABSTRACT:
A dual focal length ophthalmic lens is formed from a birefringent material with its fast and slow axes perpendicular to the user's visual axis. The dual focal property arises due to the differing indices of refraction of the birefringent material for light polarized parallel to the fast and slow axes. Light emanating from far objects having one polarization and light emanating from near objects having the opposite polarization are both focused onto the user's retina. Depending upon which object is being viewed, an in-focus and a blurred image appear simultaneously on the user's retina. The ability of the user's eye/brain system to distinguish between the two images provides bifocal action from a single lens. The invention may take the form of a spectacle, contact, or intraocular implant lens.
REFERENCES:
patent: 3520592 (1970-07-01), Leib et al.
patent: 3536921 (1970-10-01), Caulfield
patent: 3592533 (1971-07-01), Braunhut
patent: 3944346 (1976-03-01), Shindler
patent: 4155122 (1979-05-01), Budmigar
patent: 4302081 (1981-11-01), Tseutaki
patent: 4550984 (1985-11-01), Raymond
patent: 4637697 (1987-01-01), Freeman
patent: 4641934 (1987-02-01), Freeman
patent: 4642112 (1987-02-01), Freeman
patent: 4655565 (1987-04-01), Freeman
patent: 4783152 (1988-11-01), Nishimoto
W. N. Charman, "Diffractive Bifocal Contact Lenses", Contax, 11, (May 1986).
S. St. Cyr, "The Holographic Bifocal Contact Lens", Holosphere, vol. 15, No. 5, (Fall 1988).
Environmental research Institute of Michigan
Sugarman Scott J.
LandOfFree
Bifocal ophthalmic lens constructed from birefringent material does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Bifocal ophthalmic lens constructed from birefringent material, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Bifocal ophthalmic lens constructed from birefringent material will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-832687