MULTIFUNCTIONAL OPTHALMIC MEASUREMENT SYSTEM
1 Assignment
0 Petitions
Accused Products
Abstract
A wavefront measurement system, for measurement of aberrations in the eye, and for measurement of the topography of the cornea of the eye. The system differs from previously available systems in that the wavefront measurement of the eye'"'"'s aberrations can be performed as a function of eye accommodation. Furthermore, methods for reducing corneal reflection are described. Additionally, the use of a very short focal length Hartman Shack lenslet array enables a very wide range of low order aberrations, up to ±25 diopters, to be measured without any refocusing or motion of the system. Also, methods are described for enabling the presence of defects within the eye to be determined using the aberration measurement system. Another embodiment captures the pupil centering position without any projected illumination pattern being used, so that a subsequent accurate centering and focusing procedure can commence at the initially captured position, thus reducing measurement time.
-
Citations
101 Claims
-
1-63. -63. (canceled)
-
64. A method of performing measurements on the eye of a subject, said method comprising:
-
providing a combination wavefront analysis and corneal topography system, the corneal topography system including a visual camera system; generating visual images of said eye using said camera system; analyzing said visual images obtained by said camera system to determine the central point of the pupil of said eye; laterally adjusting said combination wavefront analysis and corneal topography system to co-align their optical axis and the central point of the pupil; projecting an image onto said eye; and using image processing of the reflection of said projected image from said eye to improve the accuracy of centering of said eye relative to said combination wavefront analysis and corneal topography system. - View Dependent Claims (65, 66, 67, 68, 69, 70, 71, 72)
-
-
73. A system for performing a wavefront measurement on the eye of a subject, comprising:
-
a Shack-Hartman wavefront analysis system analyzing light emerging from said eye after reflection from the retina of said eye; and a fixation target unit, adjustable such that the effective distance of said target from said subject can be varied over a range from the subject'"'"'s near vision to effective infinity; wherein said fixation target unit is adjustable along the measurement axis independently of the position of said wavefront analysis system along the measurement axis. - View Dependent Claims (74, 75, 76)
-
-
77. A system for reducing the effects of corneal reflection when making measurements on an eye of a subject, said system comprising:
-
an illuminating beam, at least partly polarized, incident on the eye of the subject, said beam being directed at the eye along an off-axial measurement path such that reflection from the anterior surface of the cornea is directed away from the measurement path because of the curvature of the corneal surface; and at least one reflecting surface interposed in said measurement path, said reflecting surface being of such a nature and so aligned that it has different reflectivities to light of different polarization impinging thereon. - View Dependent Claims (78, 79)
-
-
80. A system for measuring aberrations introduced by an eye, said system comprising:
-
a light source adapted to provide retinal illumination such that part of said retina illumination is reflected from the retina and exits said eye as a wavefront; a lenslet array located along an optical path of the wavefront for receiving the wavefront and for creating a plurality of spot images thereof; a detector array that detects the spot images formed by said lenslet array; and a calculating module receiving signals from said detector array and adapted to determine the wavefront aberrations from said signals; wherein the focal length of the lenslets of said array are sufficiently short that said apparatus can cover measurements of low order aberration over a range found in essentially any subject, without need for refocusing. - View Dependent Claims (81, 82, 83, 84, 85, 86, 87, 88, 89)
-
-
90. Apparatus for coincident centering of systems for performing ophthalmic measurements on an eye, said apparatus comprising:
-
a wavefront analysis system, including a Hartman Shack array; a corneal topography system, including a visual camera system; and an illuminated centering object disposed in front of said eye, such that the illumination from said centering object is reflected from said eye and is imaged by said corneal topography system to define the centralization of said cornea in said corneal topography system; wherein said wavefront analysis system and said corneal topography system are boresighted on the same optical axis by previous alignment, such that said centering object is effective for ensuring that both said corneal topography images and said wavefront analysis system are commonly centered. - View Dependent Claims (91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101)
-
Specification