Abstract:
The invention provides multi-focal segmented lenses with boundaries that include at least one blended portion and at least one sharp portion. The lenses may possess, for example, the aesthetic advantage of blended multi-segment or progressive lenses while largely retaining the functional advantage of multi-segment lenses with sharp segment boundaries.
Abstract:
The current invention is directed to a method for designing an ophthalmic lens element, the method comprising the steps of determining a wavefront aberration of an eye in a reference plane, wherein the wavefront aberration of the eye can be described by a first series of polynomials of ascending order up to a first specific order and corresponding first coefficients; and determining a first vision correction of a second specific order to obtain an adapted ophthalmic lens element; determining at least one specified point over an aperture of the adapted ophthalmic lens element; determining a high-order wavefront aberration in the reference plane for each specified point of the adapted ophthalmic lens element, wherein the high-order wavefront aberration can be described by a third series of polynomials of ascending order above the second specific order up to and including the first specific order and corresponding third coefficients; determining a second vision correction of the second specific order for each of the specified points to obtain an optimized ophthalmic lens element based on the first vision correction up to and including the second specific order and based on combined first and third coefficients above the second specific order and up to and including the first specific order. Further, the current invention is directed to a method for manufacturing an ophthalmic lens element, a computer program product and a system for carrying out the methods.
Abstract:
An ophthalmic lens element (100) for correcting myopia in a wearer's eye is disclosed. The lens element (100) includes a central zone (102) and a peripheral zone (104). The central zone (102) provides a first optical correction for substantially correcting myopia associated with the foveal region of the wearer's eye. The peripheral zone (104) surrounds the central zone (102) and provides a second optical correction for substantially correcting myopia or hyperopia associated with a peripheral region of the retina of the wearer's eye. A system and method for dispensing or designing an ophthalmic lens element for correcting myopia in a wearer's eye is also disclosed.
Abstract:
A method and apparatus for determining resistance and pulsatility indices of a flow of material, such as the flow of blood in the human body. This may be implemented, for example, in a color flow module in an ultrasonic imaging system for display of the pulsatility or resistance index in two dimensions and in different colors to allow discrimination between veins and arteries and detection of pathologic elevation of vascular resistance in a clinical survey mode of the system. The resistance index is determined from the ratio of a unipolar variation estimate of a velocity of the flow material divided by a peak velocity. The variation estimate may be one of the following: a difference between a peak velocity of the flow of material and a second minimum (if unipolar) or negative (if bipolar) velocity of the flow of material, a standard deviation .rho. of the velocity of the flow of material, a square root of a value at a first peak of an autocorrelator of the velocity of the flow of material, and a square root of a value at a second peak of the autocorrelator of the velocity of the flow of material.
Abstract:
A method and apparatus for generating three-dimensional (3D) images of flow structures and their flow lumen using ultrasound techniques. According to one aspect of the invention, a border between a flow region and a non-flow region is used to render a three-dimensional image of the flow lumen of the flow structure. The images may be viewed in real-time and/or stored on a machine-readable medium. In one embodiment, the three-dimensional images may be manipulated in a number of viewing directions/angles/distances/positions/styles. In one embodiment, a flow lumen may be displayed using a virtual angioscopic view.
Abstract:
A method for quantitatively estimating the amount of tissue that contains moving blood using power Doppler ultrasound. A region of interest is identified from a frozen image (i.e., a snapshot screen display created by displaying the last real-time image for a given scan). The region of interest is specified by using a pointing device (e.g., a mouse). An object that contains one hundred percent blood flow and is located at the same depth as the region of interest, but not necessarily inside the region of interest, is identified and the corresponding power noted and designated as the reference power level. The display is adjusted to show the one hundred percent blood flow vessel in a designated color (such as, for example, green) and all other power levels are normalized to the reference power level. The fractional blood volume is quantitatively estimated by summing the normalized Doppler power levels in a region of interest and dividing the sum by the number of pixels in region of interest. The numerical result for the specified region of interest may be shown on the display of the ultrasound scanner.
Abstract:
A method, a system and a computer program for determining an eyeglass prescription for an eye are disclosed. Initially, information about a measurement indicative of the refractive properties of the eye is received. Subsequently, a mathematical representation of wavefront aberrations of the eye is determined from the measurement. The mathematical representation includes a multitude of polynomials, each polynomial having an azimuthal order and a radial order. Further, the mathematical representation includes at least a first polynomial group having a common radial order, wherein the common radial order is higher than two. The eyeglass prescription is determined based on a merit function, wherein each polynomial of the first polynomial group that is used in the merit function has an azimuthal order of −2, 0, or 2, respectively.
Abstract:
An array of progressive ophthalmic lens elements is disclosed. The progressive ophthalmic elements contained in the array having substantially the same addition power and substantially the same optical prescription for distance vision. Each of the progressive ophthalmic lens elements has a progressive lens design characterised by a set of parameters defining a distance zone providing a refracting power for distance vision, a near zone providing a refracting power for near vision and a corridor having a refracting power varying from that of the distance zone to that of the near zone. The progressive ophthalmic lens elements provide, for a range of values or categories of at least two lifestyle and/or biometric parameters of lens wearers, different progressive lens designs in which at least two of the lens design parameters each have a respective value or characteristic attributable to, or associated with, a particular value or category of a respective one of the lifestyle and/or biometric parameters.
Abstract:
A method of designing and/or selecting a progressive addition lens design for a wearer is disclosed. In an embodiment, the method includes displaying a graphical representation of an initial progressive addition lens design including design parameters having design values. A user interface is provided including, for each of one or more of the design parameters, a control that is adjustable over a range of levels, each level in the range being associated with a corresponding value of the respective design parameter. A control is adjusted to select a level and the selection is processed so as to substantially simultaneously update the displayed graphical representation in accordance with the selected level to provide a modified progressive lens design. A system for designing and/or selecting a progressive addition lens design for a wearer is also disclosed.
Abstract:
An optical lens element including a first surface; and a second surface of complementary curvature; at least one surface exhibiting significant deviation in curvature from a standard optical surface; the first and second surfaces in combination defining an optical zone exhibiting substantially constant mean through power along at least one meridian.