Larry Thibos - Academia.edu (original) (raw)

Papers by Larry Thibos

Research paper thumbnail of The Chromatic Eye: A New Model of Ocular Chromatic Aberration

Ophthalmic and Visual Optics

The optical apparatus of the eye presents a low-pass spatial filter to the front end of the visua... more The optical apparatus of the eye presents a low-pass spatial filter to the front end of the visual system which is a potential limiting factor for any visual task. In the well-focused eye, chromatic aberration and diffraction are thought to be the major optical factors limiting vision.1-3 Recent evidence indicates that ocular chromatic aberration can significantly reduce image contrast, resulting in loss of contrast sensitivity and visual acuity, and may also inject large artifacts into the retinal image of colored visual targets.4,5 Such problems are likely to be exacerbated by the use of achromatizing lenses6 or other optical apparatus such as clinical test instrumentation7 which may shift the eye's achromatic axis away from the fovea, thus exposing central vision to transverse aberration from which it is normally protected.8 Consequently, it is important to have available an accurate, mathematically tractable model of ocular chromatic aberration to help gauge the potential ma...

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Research paper thumbnail of Using A Shack-hartmann Wavefront Aberrometer To Measure Forward Light Scatter Caused By Tear Film Breakup

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Research paper thumbnail of The Scale and Spatial Distribution of Optical Aberrations That Accompany Tear Break-up

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Research paper thumbnail of Validation of Programmable Liquid-Crystal Lens by Use of Hartmann-Moire Wavefront Sensor

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Research paper thumbnail of Measuring Light Scatter With a Shack-Hartmann Wavefront Aberrometer

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Research paper thumbnail of Correlation of Visual Acuity, Optical Aberrations, and Light Scatter During Periods of Non-blinking in Soft Contact Lens Wearers

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Research paper thumbnail of Psychophysical study of the optical origin of starbursts

Journal of the Optical Society of America, Mar 12, 2019

Starbursts seen around small bright lights at night have been attributed to optical scatter, diff... more Starbursts seen around small bright lights at night have been attributed to optical scatter, diffraction, or aberrations. We manipulated pupil aperture and aberrations to investigate the entopic appearance of perceived starbursts. The impact of circular, annular, and wedge-shaped pupil apertures, and spherical aberration sign and magnitude were used to identify pupil sub-apertures responsible for each radial perceived starburst line. Local intensity distributions within the starbursts mapped onto unique sub-regions of the pupil of both phakic and pseudophakic eyes, consistent with the hypothesis that ocular aberrations are the cause of starbursts. In paraxially focused eyes, the size of starbursts is predicted by the amount of spherical aberration, and starburst orientation is either the same or 180 deg rotated from the pupil region that creates each starburst line. No starbursts are seen when the pupil diameter is smaller than 3 mm. Replacing the eye's natural lens with a radially symmetric and optically homogeneous intraocular lens reduced the observed number of starbursts by 50%. Geometrical optics modeling including the measured aberrations of an individual eye can reveal point spread function structure that captures some of the key elements of the entopic perceptions.

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Research paper thumbnail of Diurnal Fluctuations in Ocular Aberrations in Keratoconus

Investigative Ophthalmology & Visual Science, May 1, 2003

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Research paper thumbnail of Predicting Optical Effects of Tear Film Break Up on Retinal Image Quality Using the Shack-Hartmann Aberrometer and Computational Optical Modeling

Advances in Experimental Medicine and Biology, 2002

ABSTRACT

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Research paper thumbnail of (CL-223)QUALITY of Retinal Image with Soft Contact Lenses Designed to Correct Presbyopia

Optometry and Vision Science, Dec 1, 2000

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Research paper thumbnail of Mission: Impossible—Ghost Protocol-ameliorating the visibility of ghosting in presbyopic contact lens corrections

Contact Lens and Anterior Eye, Dec 1, 2012

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Research paper thumbnail of Impact of Positive and Negative Defocus on Visual Acuity

Investigative Ophthalmology & Visual Science, Apr 17, 2010

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Research paper thumbnail of An Experimental Model of Bifocal Vision

Ophthalmic and Visual Optics

Contact and intraocular lens designers and manufacturers have considered many strategies to provi... more Contact and intraocular lens designers and manufacturers have considered many strategies to provide presbyopes with good near and distant vision. In particular, considerable effort has been made recently to design simultaneous vision bifocal contact and intraocular lenses (CL and IOL). These simultaneous vision bifocals create dual images simultaneously on the retina (we will refer to this as monocular diplopia). Very little is known about the visual impact of such an optical situation.

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Research paper thumbnail of Validation of a Combined Corneal Topographer and Aberrometer Based on a Shack-Hartmann Wavefront Sensor

Investigative Ophthalmology & Visual Science, May 1, 2003

ABSTRACT

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Research paper thumbnail of Psychophysical Analysis of an Axonally–Induced Scotoma

Investigative Ophthalmology & Visual Science, 2005

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Research paper thumbnail of Changes in Peripheral Refractive Error Due to Accommodation and Higher Order Aberrations

Investigative Ophthalmology & Visual Science, 2008

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Research paper thumbnail of Retinal stretching limits visual acuity in myopic eyes

Investigative Ophthalmology & Visual Science, 2004

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Research paper thumbnail of Determination of the Optimum Weighting of Objective Refractions for Predicting Subjective Refraction

Investigative Ophthalmology & Visual Science, 2010

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Research paper thumbnail of What Is The Amplitude Of Accommodation Of An Aberrated Eye

Investigative Ophthalmology & Visual Science, 2011

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Research paper thumbnail of Prediction of visual acuity with combinations of wavefront aberration metrics

Investigative Ophthalmology & Visual Science, 2004

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Research paper thumbnail of The Chromatic Eye: A New Model of Ocular Chromatic Aberration

Ophthalmic and Visual Optics

The optical apparatus of the eye presents a low-pass spatial filter to the front end of the visua... more The optical apparatus of the eye presents a low-pass spatial filter to the front end of the visual system which is a potential limiting factor for any visual task. In the well-focused eye, chromatic aberration and diffraction are thought to be the major optical factors limiting vision.1-3 Recent evidence indicates that ocular chromatic aberration can significantly reduce image contrast, resulting in loss of contrast sensitivity and visual acuity, and may also inject large artifacts into the retinal image of colored visual targets.4,5 Such problems are likely to be exacerbated by the use of achromatizing lenses6 or other optical apparatus such as clinical test instrumentation7 which may shift the eye's achromatic axis away from the fovea, thus exposing central vision to transverse aberration from which it is normally protected.8 Consequently, it is important to have available an accurate, mathematically tractable model of ocular chromatic aberration to help gauge the potential ma...

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Research paper thumbnail of Using A Shack-hartmann Wavefront Aberrometer To Measure Forward Light Scatter Caused By Tear Film Breakup

Bookmarks Related papers MentionsView impact

Research paper thumbnail of The Scale and Spatial Distribution of Optical Aberrations That Accompany Tear Break-up

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Validation of Programmable Liquid-Crystal Lens by Use of Hartmann-Moire Wavefront Sensor

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Measuring Light Scatter With a Shack-Hartmann Wavefront Aberrometer

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Correlation of Visual Acuity, Optical Aberrations, and Light Scatter During Periods of Non-blinking in Soft Contact Lens Wearers

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Psychophysical study of the optical origin of starbursts

Journal of the Optical Society of America, Mar 12, 2019

Starbursts seen around small bright lights at night have been attributed to optical scatter, diff... more Starbursts seen around small bright lights at night have been attributed to optical scatter, diffraction, or aberrations. We manipulated pupil aperture and aberrations to investigate the entopic appearance of perceived starbursts. The impact of circular, annular, and wedge-shaped pupil apertures, and spherical aberration sign and magnitude were used to identify pupil sub-apertures responsible for each radial perceived starburst line. Local intensity distributions within the starbursts mapped onto unique sub-regions of the pupil of both phakic and pseudophakic eyes, consistent with the hypothesis that ocular aberrations are the cause of starbursts. In paraxially focused eyes, the size of starbursts is predicted by the amount of spherical aberration, and starburst orientation is either the same or 180 deg rotated from the pupil region that creates each starburst line. No starbursts are seen when the pupil diameter is smaller than 3 mm. Replacing the eye's natural lens with a radially symmetric and optically homogeneous intraocular lens reduced the observed number of starbursts by 50%. Geometrical optics modeling including the measured aberrations of an individual eye can reveal point spread function structure that captures some of the key elements of the entopic perceptions.

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Research paper thumbnail of Diurnal Fluctuations in Ocular Aberrations in Keratoconus

Investigative Ophthalmology & Visual Science, May 1, 2003

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Research paper thumbnail of Predicting Optical Effects of Tear Film Break Up on Retinal Image Quality Using the Shack-Hartmann Aberrometer and Computational Optical Modeling

Advances in Experimental Medicine and Biology, 2002

ABSTRACT

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Research paper thumbnail of (CL-223)QUALITY of Retinal Image with Soft Contact Lenses Designed to Correct Presbyopia

Optometry and Vision Science, Dec 1, 2000

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Research paper thumbnail of Mission: Impossible—Ghost Protocol-ameliorating the visibility of ghosting in presbyopic contact lens corrections

Contact Lens and Anterior Eye, Dec 1, 2012

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Research paper thumbnail of Impact of Positive and Negative Defocus on Visual Acuity

Investigative Ophthalmology & Visual Science, Apr 17, 2010

Bookmarks Related papers MentionsView impact

Research paper thumbnail of An Experimental Model of Bifocal Vision

Ophthalmic and Visual Optics

Contact and intraocular lens designers and manufacturers have considered many strategies to provi... more Contact and intraocular lens designers and manufacturers have considered many strategies to provide presbyopes with good near and distant vision. In particular, considerable effort has been made recently to design simultaneous vision bifocal contact and intraocular lenses (CL and IOL). These simultaneous vision bifocals create dual images simultaneously on the retina (we will refer to this as monocular diplopia). Very little is known about the visual impact of such an optical situation.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Validation of a Combined Corneal Topographer and Aberrometer Based on a Shack-Hartmann Wavefront Sensor

Investigative Ophthalmology & Visual Science, May 1, 2003

ABSTRACT

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Psychophysical Analysis of an Axonally–Induced Scotoma

Investigative Ophthalmology & Visual Science, 2005

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Changes in Peripheral Refractive Error Due to Accommodation and Higher Order Aberrations

Investigative Ophthalmology & Visual Science, 2008

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Retinal stretching limits visual acuity in myopic eyes

Investigative Ophthalmology & Visual Science, 2004

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Determination of the Optimum Weighting of Objective Refractions for Predicting Subjective Refraction

Investigative Ophthalmology & Visual Science, 2010

Bookmarks Related papers MentionsView impact

Research paper thumbnail of What Is The Amplitude Of Accommodation Of An Aberrated Eye

Investigative Ophthalmology & Visual Science, 2011

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Prediction of visual acuity with combinations of wavefront aberration metrics

Investigative Ophthalmology & Visual Science, 2004

Bookmarks Related papers MentionsView impact