Abstract: A computer, a high resolution monitor and a patient interface is utilized to implement a visual contrast sensitivity function measurement test. More specifically, a computerized video system is configured to implement a tilted-grating forced choice contrast sensitivity function test. The invention utilizes known measurement methods for the visual contrast sensitivity function and automates their use by computerizing the system and couples it with a patient-interactive user interface in order to produce an accurate quantitative result.

Abstract: A computer, a high resolution monitor and a patient interface is utilized to implement a visual contrast sensitivity function measurement test. More specifically, a computerized video system is configured to implement a tilted-grating forced choice contrast sensitivity function test. The invention utilizes known measurement methods for the visual contrast sensitivity function and automates their use by computerizing the system and couples it with a patient-interactive user interface in order to produce an accurate quantitative result.

Abstract: The system and methods are made to apply interferometry to ophthalmic applications. The system makes use of a low-coherence interferometer to obtain a plurality of measurements of a contacts lens. The system and methods characterizes the surface profile of both surfaces of a contact lens, a thickness profiles, and combines these measurements with an index information to reconstruct a complete model of the contact lens.

Abstract: A computer, a high resolution monitor and a patient interface is utilized to implement a visual contrast sensitivity function measurement test. More specifically, a computerized video system is configured to implement a tilted-grating forced choice contrast sensitivity function test. The invention utilizes known measurement methods for the visual contrast sensitivity function and automates their use by computerizing the system and couples it with a patient-interactive user interface in order to produce an accurate quantitative result.

Abstract: The system and methods are made to apply interferometry to ophthalmic applications. The system makes use of a low-coherence interferometer to obtain a plurality of measurements of a contacts lens. The system and methods characterizes the surface profile of both surfaces of a contact lens, a thickness profiles, and combines these measurements with an index information to reconstruct a complete model of the contact lens.

Abstract: The system and methods are made to apply interferometry to ophthalmic applications. The system makes use of a low-coherence interferometer to obtain a plurality of measurements of a contacts lens. The system and methods characterizes the surface profile of both surfaces of a contact lens, a thickness profiles, and combines these measurements with an index information to reconstruct a complete model of the contact lens.

Abstract: The system and methods are made to apply interferometry to ophthalmic applications. The system makes use of a low-coherence interferometer to obtain a plurality of measurements of a contacts lens. The system and methods characterizes the surface profile of both surfaces of a contact lens, a thickness profiles, and combines these measurements with an index information to reconstruct a complete model of the contact lens.

Abstract: The system and methods are made to apply interferometry to ophthalmic applications. The system makes use of a low-coherence interferometer to obtain a plurality of measurements of a contacts lens. The system and methods characterizes the surface profile of both surfaces of a contact lens, a thickness profiles, and combines these measurements with an index information to reconstruct a complete model of the contact lens.

Abstract: The system and methods are made to apply interferometry to ophthalmic applications. The system makes use of a low-coherence interferometer to obtain a plurality of measurements of a contacts lens. The system and methods characterizes the surface profile of both surfaces of a contact lens, a thickness profiles, and combines these measurements with an index information to reconstruct a complete model of the contact lens.

Abstract: A computer, a high resolution monitor and a patient interface is utilized to implement a visual contrast sensitivity function measurement test. More specifically, a computerized video system is configured to implement a tilted-grating forced choice contrast sensitivity function test. The invention utilizes known measurement methods for the visual contrast sensitivity function and automates their use by computerizing the system and couples it with a patient-interactive user interface in order to produce an accurate quantitative result.

Abstract: The system and methods are made to apply interferometry to ophthalmic applications. The system makes use of a low-coherence interferometer to obtain a plurality of measurements of a contacts lens. The system and methods characterizes the surface profile of both surfaces of a contact lens, a thickness profiles, and combines these measurements with an index information to reconstruct a complete model of the contact lens.

Abstract: An in vivo method of characterizing dynamic tear films has been developed using a near infrared phase-shifting interferometer. This interferometer continuously measures light reflected from the tear film, allowing precision analysis of the dynamic surface topography. Movies showing the tear film behavior may be generated along with quantitative metrics describing the tear film surface as it changes in time.

Abstract: An in vivo method of characterizing dynamic tear films has been developed using a near infrared phase-shifting interferometer. This interferometer continuously measures light reflected from the tear film, allowing precision analysis of the dynamic surface topography. Movies showing the tear film behavior may be generated along with quantitative metrics describing the tear film surface as it changes in time.

Abstract: A system and method for analyzing the dynamics of fluid layers on contact lenses utilizes phase shifting interferometry to quickly and accurately model the time-evolution of the fluid layers. The system and method are utilized for in vitro studies.

Abstract: A finite impulse response digital filter is designed for boosting mid-spatial frequencies as opposed to the frequencies near the sensor resolution limit. The digital filter's boost is centered on frequencies at about half the Nyquist frequency. To prevent over-boosting or enhancement of noise, the detail signal can be run through a coring filter to remove any low amplitude detail signal that resulted from noise.

Abstract: Method and apparatus are disclosed for providing absolute Moire distance measurements of a diffusely reflective surface from a reference position. More particularly, a first grating is located, formed, or printed on the diffusely reflective surface. An image of the first grating is formed on a second grating or detector array by imaging means for generating a Moire pattern that is detected by a detector means. At the reference position of the diffusely reflective surface relative to the imaging means, the periods of the image of the first grating and the second grating match. Movement of the diffusely reflective surface from the reference position in a direction normal thereto, produces a spatially varying intensity pattern at the detector means which results from the shifting and magnification mismatch between the pattern of the image of the first grating and the pattern of the second grating.

Abstract: Method and apparatus are disclosed for providing Moire distance and displacement measurements of a diffusely reflective surface of an object or support. More particularly, a first grating is physically located, formed, or printed on the diffusely reflective surface. An image of the first grating is formed on a second grating by an imaging means for generating a Moire pattern behind the second grating. At an initial position of the diffusely reflective surface relative to the imaging means, the periods of the image of the first grating and the second grating match. Movement of the diffusely reflective surface in a direction normal thereto and away from the initial position produces a spatially varying intensity pattern caused by the Moire between a shifting and changing magnified pattern of the image of the first grating and a pattern of the second grating.

Abstract: A process for scanning halftoned images with a sampled or electronic imaging system includes the steps of first optically low-pass filtering the scene, then oversampling the scene at a rate several times that required for display bandwidth, and finally putting the resulting data through an electronic or digital low-pass filter/resampling operation to reduce the system data load. The oversampling advantageously shifts unwanted aliasing between the halftone and sampling frequencies to frequencies above the display bandwidth, so that the aliasing may then be filtered out without affecting signals within the bandwidth of the display.

Abstract: The measurement range of Moire contouring techniques is extended beyond the Nyquist frequency limit by constraining the reconstruction of a surface contour according to a priori knowledge about the surface. In one example the a priori knowledge is that the surface is smooth, being described by a function having continuous derivatives, and the location of a region where the surface changes by less than C/2 per sample. In another example, the a priori knowledge is the location and height of a step discontinuity to within C/2, where C is the contour interval.

Abstract: A technique is described for extending the measurement range of interferometry past the Nyquist limit of the sampling frequency of the interferogram. The absolute phase values measured by an interferometer are reconstructed by applying constraints based upon a priori knowledge of the absolute phase values. The constraints include the knowledge that one or more derivatives of the spatial distribution of phase values is a continuous function, and the knowledge of step heights to within .lambda./2.