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US 4,728,183 AGranted
Ophthalmic lens for observing the fundus of the eye
AssigneeOcular Instruments, Inc.
InventorsGregory L. Heacock, Martin A. Mainster, Phillip J. Erickson
Life of this patent
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Abstract
An ophthalmic lens utilized for observing the fundus of an eye using through the lens illumination and for delivering a focused laser beam to the fundus includes a contact lens and an aspheric entry lens. In combination, the lenses provide an aerial image of the fundus anterior to the entry lens.
Claims9
An ophthalmic lens for observing the fundus of the eye comprising:
- a contact lens having a posterior surface and an anterior surface, said posterior surface having a radius of curvature substantially the same as the anterior surface of a cornea, the anterior surface of the contact lens having a radius of curvature such that the light rays emerging from the patient's eye through the crystalline lens and cornea are substantially parallel as they exit in an anterior direction from the contact lens,
- an entry lens positioned anterior to the contact lens, the optical axis of the contact lens and said entry lens being substantially coincident, said entry lens being aspheric, the posterior and anterior surfaces of said entry lens being constructed and said entry lens being spaced from said contact lens so as to collect said parallel light rays emerging from the contact lens and produce an aerial image anterior to and in close proximity to the entry lens, the surfaces of said entry lens being defined by the formula:
- ##EQU2## wherein
- C=(1/R),
- E=b+1,
- and
- K.sup.2 =x.sup.2 +y.sup.2,
- wherein for the anterior surface of the lens R ranges from 14 mm to 50 mm and b ranges from -54 to -4, and wherein the posterior surface of said lens, R ranges from 10 mm to 25 mm and b ranges from -0.6 to -2, and
- holder means for interconnecting and fixing said lenses relative to each other.
6 more elements
An ophthalmic lens for observing the fundus of the eye comprising:
- a contact lens having a posterior surface and an anterior surface, said posterior surface having a radius of curvature substantially the same as the anterior surface of a cornea, the anterior surface of the contact lens having a radius of curvature such that the light rays emerging from the patient's eye through the crystalline lens and cornea are substantially parallel as they exit in an anterior direction from the contact lens,
- an entry lens positioned anterior to the contact lens, the optical axis of the contact lens and said entry lens being substantially coincident, said entry lens being aspheric, the posterior and anterior surfaces of said entry lens being constructed and said entry lens being spaced from said contact lens so as to collect said parallel light rays emerging from the contact lens and produce an aerial image anterior to and in close proximity to the entry lens, the surfaces of said entry lens being defined by the formula:
- ##EQU3## wherein
- C=(1/R),
- E=b+1,
- and
- K.sup.2 =x.sup.2 +y.sup.2,
- wherein for the anterior surface of the lens R ranges from 10 mm to 100 mm and b ranges from -900 to -7, and wherein for the posterior surface of said lens, R ranges from 6.5 mm to 11 mm and b ranges from -0.54 to -1.08, and
- holder means for interconnecting and fixing said lenses relative to each other.
6 more elements
Dependencies are inferred from the claim text.