In a method for measuring the positions of centers of curvature of optical surfaces of a single- or multi-lens optical system, an imaging lens system images an object plane into a first and a second image plane. The first image plane is produced by a first ancillary lens system having a first focal length and defining a first beam path, while the second image plane is produced by a second ancillary lens system having a second focal length that is different from the first focal length and defining a second beam path that is different from the first beam path. An object arranged in the object plane is then imaged simultaneously or sequentially at the first and the second image plane by means of measuring light. Reflections of the measuring light at optical surfaces of the optical system are detected by means of a spatially resolving light sensor. The actual positions of the first and the second center of curvature are calculated from the detected reflexes.

Contact lenses often comprise a coating containing water so as to enhance comfort when being worn on the eye. The present invention is useful to determine the water content of the coating of a contact lens. To determine the water content of the coating, the lens having the coating to be measured is arranged under water. The reflectivity of the surface of the lens is then determined with the aid of a Chromatic sensor system.

A reflectivity test circuit is described. The reflectivity test circuit includes a symmetric structure that cancels errors in the reflectivity measurements. In particular, the reflectivity test circuit includes an optical waveguide that is optically coupled to two optical ports and two optical couplers. The optical couplers are optically coupled to adjacent optical waveguides, at least one of which is optically coupled to a third optical port and the mirror. Moreover, a length of the optical waveguide is chosen to match the round-trip optical path length in at least the one of the adjacent optical waveguides. During operation, control logic determines the reflectivity of the mirror based at least on a ratio of an optical power measured on one of the two optical ports to an input optical power on the third optical port.

A method for testing a laser device configured to emit pulsed, focused laser radiation includes providing an artificial eye body with a pattern that simulates a pupil and/or an iris structure. An irradiation test object is arranged above the pattern. The irradiation test object is separate from the eye body and is made of a material that is modifiable by the laser radiation. The laser radiation is applied to the irradiation test object according to a predefined application profile, so that a material modification that corresponds to the application profile is generated in the irradiation test object.

In a method for measuring the positions of centres of curvature of optical surfaces of a single- or multi-lens optical system, an imaging lens system images an object plane into a first and a second image plane. The first image plane is produced by a first ancillary lens system having a first focal length and defining a first beam path, while the second image plane is produced by a second ancillary lens system having a second focal length that is different from the first focal length and defining a second beam path that is different from the first beam path. An object arranged in the object plane is then imaged simultaneously or sequentially at the first and the second image plane by means of measuring light. Reflections of the measuring light at optical surfaces of the optical system are detected by means of a spatially resolving light sensor. The actual positions of the first and the second centre of curvature are calculated from the detected reflexes.

In a method for measuring the positions of centres of curvature of optical surfaces of a single- or multi-lens optical system, an imaging lens system images an object plane into a first and a second image plane. The first image plane is produced by a first ancillary lens system having a first focal length and defining a first beam path, while the second image plane is produced by a second ancillary lens system having a second focal length that is different from the first focal length and defining a second beam path that is different from the first beam path. An object arranged in the object plane is then imaged simultaneously or sequentially at the first and the second image plane by means of measuring light. Reflections of the measuring light at optical surfaces of the optical system are detected by means of a spatially resolving light sensor. The actual positions of the first and the second centre of curvature are calculated from the detected reflexes.

A lens focusing device includes a lens holding module for clamping at least one test lens to be tested, a replaceable chart display module, and a focal length shortening module. The replaceable chart display module includes a frame structure, a first chart display element detachably disposed on the frame structure, and a plurality of second chart display elements detachably disposed on the frame structure, and each second chart display element is inclined at a predetermined angle relative to the first chart display element. The focal length shortening module includes a first focal length shortening structure and a plurality of second focal length shortening structures. The first focal length shortening structure is disposed between the at least one test lens and the first chart display element, and each second focal length shortening structure is disposed between the at least one test lens and the corresponding second chart display element.

A lens array includes a plurality of lenses that collect divided test light and form spots. Each lens includes a lens member, and a light shielding mask provided concentric to the lens member along a perimeter edge thereof, the light shielding mask shielding a part of the light and transmitting a part of the light. The light shielding mask is formed to satisfy a predetermined mathematical condition of light transmission.

A transparency evaluation device includes a skin index calculation unit that calculates at least one of a luminance component in a captured image obtained by photographing a skin, a color component in the captured image, and an amount of generation of negative factors in which the luminance component or the color component in the captured image changes locally, as a first index, obtains at least one of an intensity distribution of the luminance component and an intensity distribution of the color component in the captured image, and calculates at least one of smoothness of a change in the luminance component and smoothness of a change in the color component as a second index based on the intensity distributions, and a transparency evaluation unit that evaluates transparency of the skin based on an overall index in which the first index and the second index are combined.

Disclosed is a reflective encoder which is capable of measuring movement amount and detecting movement direction by using one emergent light beam, and achieving high reliability and miniaturization through a simple structure. In the reflective encoder, a light beam emitted by a laser oscillator is caused to be incident on a reflective diffraction grating disposed on a side of a scale, and diffracted light beams reflected by the reflective diffraction grating are received by light receiving elements. An interference optical system is provided between the light receiving elements and the reflective diffraction grating. An optical system is thus constructed to measure movement amount and detect movement direction by using only one emergent light beam.