Optics: eye examining – vision testing and correcting – Eye examining or testing instrument – Objective type
Reexamination Certificate
2000-04-28
2002-01-15
Manuel, George (Department: 3737)
Optics: eye examining, vision testing and correcting
Eye examining or testing instrument
Objective type
Reexamination Certificate
active
06338559
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to devices and methods for improving vision and retinal imaging, and particularly, to such devices and methods for improving a person's vision and retinal imaging by correcting higher-order monochromatic ocular aberrations and ocular chromatic aberrations.
2. Description of Related Art
Despite significant advances in spectacle and contact lens design, ophthalmic lenses for the most part only correct up to the second-order ocular aberrations known as defocus and astigmatism. Higher-order monochromatic ocular aberrations such as spherical aberration, coma, and a variety of irregular aberrations are left uncorrected by spectacles, contact lenses, corneal reshaping, inlays, onlays and other current vision correction techniques. These higher order aberrations of the eye blur images formed on the retina resulting in degraded visual performance, and also blur images taken of the living human retina. Until recently there did not exist a rapid or efficient device or approach for quantitatively measuring the irregular higher-order aberrations of the eye, nor have there been made available any practical mechanisms to correct the monochromatic aberrations of the eye other than defocus and astigmatism.
Liang et al., J. Opt. Soc. Am. A., Volume 11, Number 7, pp. 1949-1957, July 1994, the disclosure of which is incorporated by reference herein, disclosed a Hartmann-Shack wavefront sensor that they used to measure the monochromatic wave aberrations of the human eve. They did this by sensing the wavefront emerging from the eye produced by the retinal reflection of a focused light beam on the fovea. Using the system disclosed therein, the authors were able to measure only up to fourth-order polynomial functions. However, the wavefront fitting with polynomials only up to fourth order does not provide a complete description of the eye's aberrations. Subsequently, Williams, et al. U.S. Pat. No. 5,777,719, the disclosure of which is incorporated by reference herein in its entirety, described an improvement on the wavefront sensor used by Liang et al. that provided measurement data and correction for at least fifth-order monochromatic aberrations and higher. By using a deformable mirror in combination with their modified wavefront sensor apparatus, Williams et al. were able to measure and correct for complex aberrations that are not conventionally corrected by spectacles, contact lenses, other ocular devices, or surgical modification of the eye. In addition, as described therein, Williams et al. described a system that provided retinal images of an unprecedented quality.
Liang et al. Supernormal vision and high resolution retinal imaging through adaptive optics. J. Opt. Soc. Am. A., 14, 2884-2892 (1997) describe the use of adaptive optics to measure and correct the monochromatic wave aberrations of the eye. They found that correcting the higher order monochromatic aberrations provided a six-fold increase in contrast sensitivity when viewing a monochromatic grating with 27.5 cycles per degree (cpd) through a 6.0 mm pupil. However. they measured contrast sensitivity only in monochromatic light and at one spatial frequency. which are not representative of normal everyday viewing conditions.
It is also well known that the human eye suffers from chromatic aberrations. There are numerous references about attempts to analyze the effect of chromatic aberration on vision. Campbell and Gubish, J. Physiol., 192, pp. 345-358 (1967) reported, with respect to chromatic difference of focus (longitudinal chromatic aberration), that there was insignificant improvement in contrast sensitivity between white light and monochromatic light over a 10 to 40 cpd range of spatial frequencies.
Thibos et al., Optometry and Vision Science, 68, 8, pp. 599-607 (1991) asked the question whether chromatic aberration significantly affects vision. and if so, how, why and by how much? They concluded that a) axial (longitudinal) chromatic aberration results in only moderate contrast sensitivity reduction and minor visual acuity loss; b) chromatic difference of magnification has little effect on visual performance; and c) transverse chromatic aberration is significant for foveal vision only when the pupil is laterally displaced. The prevailing explanation for the unremarkable impact of chromatic aberration on vision was that chromatic aberration is most severe at the spectral extremes where the photopic spectral sensitivity of the eye is low.
Furthermore, the many studies that have looked into the effect of chromatic aberration on vision and retinal image quality have not considered the synergistic effect of chromatic aberration and higher-order monochromatic aberrations on visual performance.
In an effort to improve vision, the inventors have recognized a need to evaluate visual performance under normal viewing conditions and. consequently, to determine the extent to which the correction of only second-order aberrations, higher-order aberrations, or chromatic aberration, either alone or in combination, effect an improvement in visual ability. Accordingly, there is a need for methods and apparatus to evaluate the affects of aberrations on human vision, and which provide better vision and retinal imaging through aberration correction.
SUMMARY OF THE INVENTION
The present invention is generally directed to device and method embodiments for improving human visual performance and retinal imaging, and more particularly, such devices and methods are directed to the evaluation and improvement of human visual performance and higher quality retinal imaging based upon the combined correction of higher-order monochromatic aberrations and chromatic aberration.
An embodiment of the invention is described by an optical system for improving a person's vision that includes a higher-order phase compensation element and a light amplitude modifying element. A higher-order phase compensation element can be used to provide higher order monochromatic aberration correction, while a light amplitude modifying element can be used to provide correction for chromatic aberration. In an aspect of this embodiment the higher-order phase compensation element and the light amplitude modifying element are resident in a common optical component. In an alternative aspect, the higher-order phase compensation element and the light amplitude modifying element are each resident in a separate optical component.
Another embodiment of the invention is directed to an ocular component for improving a person's visual ability. The component has at least a shape adapted to correct a measured higher-order monochromatic ocular aberration. In addition, the ocular component has a non-uniform transmission over at least a portion of a surface thereof for correcting an ocular chromatic aberration. In an aspect of this embodiment, the pupil diameter of the eye is effectively reduced by artificial apodization to attenuate the detrimental effects of aberrations on the eye's visual performance.
Another embodiment of the invention is directed to providing improved high resolution images of the retina. The system for producing such images can advantageously use a broadband light source for increased illumination, while image quality is enhanced by correcting higher-order monochromatic aberrations and chromatic aberration.
A method embodiment of the invention is directed to improving a person's measurable visual benefit and includes correcting ocular higher-order monochromatic aberrations and in addition correcting chromatic aberration, preferably and substantially axial chromatic aberration. Preferred methods for correcting the higher-order monochromatic aberrations include providing a deformable mirror or other phase compensating element such as, e.g., an LCD or a MEMS device, or more preferably, a contact lens, an IOL, an inlay, an onlay, or corneal shaping by refractive surgery or photoablation, for example, all of which suitably are adapted to provide appropriate phase c
Guirao Antonio
Williams David R.
Yoon Geun-Young
Blank Rome Comisky & McCauley LLP
Manuel George
University of Rochester
LandOfFree
Apparatus and method for improving vision and retinal imaging does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus and method for improving vision and retinal imaging, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and method for improving vision and retinal imaging will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2817332