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Characteristics of the thick, compound refractive lens
Applied Optics, 2003A compound refractive lens (CRL), consisting of a series of N closely spaced lens elements each of which contributes a small fraction of the total focusing, can be used to focus x rays or neutrons. The thickness of a CRL can be comparable to its focal length, whereupon a thick-lens analysis must be performed.
Richard H, Pantell +5 more
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Application of Hydrogel Lens Average Thickness
Optometry and Vision Science, 1984The equation for the average thickness of a hydrogel lens is a complex function. This report gives a simple method of estimating this parameter. By structuring the information into nomograms, an accurate system is derived which facilitates the design of a contact lens to provide a required average oxygen transmissibility.
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Laser differential confocal lens thickness measurement
Measurement Science and Technology, 2012Based on the property that the absolute zero of an axial intensity curve exactly corresponds to the focus of the objective in a differential confocal system (DCS), a new laser differential confocal lens thickness measurement is proposed to achieve the high-precision non-contact measurement of lens thickness. The proposed approach uses the absolute zero
Yun Wang +3 more
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2020
Any real lens is a thick lens, meaning that it has a non-zero lens thickness t , which is the axial separation between the vertexes of the two refracting surfaces. Lens thickness is a nondirectional distance (therefore, is always positive), measured at the center of the lens along the optical axis (i.e., the lens is not tilted), regardless of the shape
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Any real lens is a thick lens, meaning that it has a non-zero lens thickness t , which is the axial separation between the vertexes of the two refracting surfaces. Lens thickness is a nondirectional distance (therefore, is always positive), measured at the center of the lens along the optical axis (i.e., the lens is not tilted), regardless of the shape
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The Definition of Thickness for a Lens
Optometry and Vision Science, 1979The thickness of a lens depends upon the direction of the measuring vector. The thickness as commonly used from the sagittal height formula does not give the path length for movement of gas, water, and heat through a lens. Furthermore, the amount of gas, water, or heat moving through a lens depends upon an areal average thickness, not central thickness.
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A Satisfying “Thick Lens” Experiment
American Journal of Physics, 1957An elementary experiment is described in which an object-image relationship for a thick lens is determined both by experiment and by calculations involving easily determined lens parameters. The two methods have over-all errors of less than 6% and agree quite well.
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Journal of The British Contact Lens Association, 1986
Abstract Current textbooks describe how the edge thickness of a contact lens measured parallel to the axis ofsymmetry, maybe calculated. Equations have been published for calculation of radial edge thickness either along the front optic radius or along an extrapolation of the back optic radius.
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Abstract Current textbooks describe how the edge thickness of a contact lens measured parallel to the axis ofsymmetry, maybe calculated. Equations have been published for calculation of radial edge thickness either along the front optic radius or along an extrapolation of the back optic radius.
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Noncontact measurement of central lens thickness
2005[no abstract available]
Kunkel, Matthias, Schulze, Jochen
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Lens thickness growth in humans
Clinical & Experimental Ophthalmology, 2013Robert C, Augusteyn +2 more
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Transition from a Thin Lens to a Thick Lens
20094.1 Introduction It was shown under Chapters 2 and 3 that the âthin lensâ concept is an extremely useful one for preliminary calculations and analysis as well as a general design tool. Determining the difference in performance between that fictitious thin lens and a realistic thick lens is an interesting exercise which confirms the statement ...
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