Extended depth of focus imaging: a review

Zalevsky, Zeev

doi:10.1117/6.0000001

Cited by 41 publications

(33 citation statements)

References 55 publications

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“…The intermediate focus is between the far and near foci and for such small IOL-pupils (2.0 to 3.0 mm, where the effects of the SA and light scattering have proved to play a minor role), it is well known that the depth of focus increases. [33] Thus, the smaller the pupil the more extended the depth of focus of the far and near foci and, as a consequence, the smaller the fraction of the energies (I pinh ) near and (I pinh ) f ar that are out of focus at the intermediate plane (see Figures 9(b) and 9(c)). This fact becomes more evident when the focal segment corresponding to the depth of focus of both the near and far foci reach one another or even overlap at the intermediate focus plane (Figure 9(c)).…”

Section: Discussionmentioning

confidence: 97%

Energy efficiency of a new trifocal intraocular lens

Vega

Alba-Bueno

Millán

2014

J. Eur. Opt. Soc.-Rapid Publ.

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The light distribution among the far, intermediate and near foci of a new trifocal intraocular lens (IOL) is experimentally determined, as a function of the pupil size, from image analysis. The concept of focus energy efficiency is introduced because, in addition to the theoretical diffraction efficiency of the focus, it accounts for other factors that are naturally presented in the human eye such as the level of spherical aberration (SA) upon the IOL, light scattering at the diffractive steps or the depth of focus. The trifocal IOL is tested in-vitro in two eye models: the aberration-free ISO model, and a so called modified-ISO one that uses an artificial cornea with positive spherical SA in instead. The SA upon the IOL is measured with a Hartmann-Shack sensor and compared to the values of theoretical eye models. The results show, for large pupils, a notorious reduction of the energy efficiency of the far and near foci of the trifocal IOL due to two facts: the level of SA upon the IOL is larger than the value the lens is able to compensate for and there is significant light scattering at the diffractive steps. On the other hand, the energy efficiency of the intermediate focus for small pupils is enhanced by the contribution of the extended depth of focus of the near and far foci. Thus, while IOLs manufacturers tend to provide just the theoretical diffraction efficiency of the foci to show which would be the performance of the lens in terms of light distribution among the foci, our results put into evidence that this is better described by using the energy efficiency of the foci.

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Section: Discussionmentioning

confidence: 97%

Energy efficiency of a new trifocal intraocular lens

Vega

Alba-Bueno

Millán

2014

J. Eur. Opt. Soc.-Rapid Publ.

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“…Accordingly, image contrast is divided into different planes and has therefore lower values than with a monofocal IOL. Finally, efforts were made to develop IOL with extended depth of focus to permit reading without accommodation at a variety of distances [1]. It is clear that the extended depth of focus design is at the cost of image contrast.…”

Section: Introductionmentioning

confidence: 99%

A Rapid and Convenient Procedure to Evaluate Optical Performance of Intraocular Lenses

Schaeffel

Kaymak²

2014

Photonics

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A new portable lens scanner was developed and tested for measuring focal lengths and relative contrast transfer of mono-and multifocal intraocular lenses (IOLs). A photograph of a natural scene was imaged in white light through an IOL in a water-filled cuvette, with their +21D base power largely neutralized by a −20D trial lens, using a USB monochrome video camera that could be focused via a laptop-controlled stepping motor from −8.5 to + 8.0D. The output of 10000 ON-OFF antagonistic "receptive fields" measuring the video image with adjustable diameter was continuously recorded by custom written software to quantify focus and relative contrast. Six monofocal and four multifocal IOLs, as well as two radial refractive gradient (RRG) lenses were measured. After calibration with trial lenses the optical powers and relative contrast transfer of mono-and multifocal IOLs were readily measured. Refractive power profiles measured in RRG lenses closely matched data obtained from the manufacturer. The lens scanner uses a rapidly operating procedure, is portable and can be used to verify positions of the focal planes of mono-and multifocal IOLs in less than 3 s.

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“…They fall into one of three categories: refractive, diffractive, or interferometric with postprocessing. An extensive overview of such methods is given in [5]. The technique described in this paper falls under none of these categories.…”

Section: Introductionmentioning

confidence: 99%

Extending the depth of focus in tomography systems for glass lattice three-dimensional mapping

2013

Self Cite

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This paper deals with the development of a computed optical tomography system designed and built to inspect glass lattices to locate various impurities inside the bulk. We focus on the investigation of the potential benefit in the usage of extended depth of focus optics for that application. The quality of 3D reconstruction for the application of glass lattice defect identification is tested numerically and experimentally against the corresponding result obtained with conventional optics.

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Extended depth of focus imaging: a review

Abstract: We review approaches for extending the depth of focus of different imaging systems including the human vision system. Approaches involving digital postprocessing as well as different types of all-optical techniques are discussed.

Cited by 41 publications

References 55 publications

Energy efficiency of a new trifocal intraocular lens

Energy efficiency of a new trifocal intraocular lens

A Rapid and Convenient Procedure to Evaluate Optical Performance of Intraocular Lenses

Extending the depth of focus in tomography systems for glass lattice three-dimensional mapping

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