This paper presents a novel approach to depth recovery from image blur by zooming. We first discuss the optical properties of a zoom lens system; the image blur varies according to zoom as well as focus and iris settings. Then a thin lens based camera model is proposed that is characterized by the effective focal length and lens diameter. Using this model, we have proved that the depth informat...

The possibility of integration of two important categories of optical components, i.e., circular polarizer and lens, into a thin plasmonic metasurface is examined, for the realistic case when metal losses cannot be neglected, for example when operating in the visible spectrum, or at infrared when non-noble metals are used. We introduce a metasurface made of nanoantennas that offer enough degree...

A perfect lens with unlimited resolution has always posed a challenge to both theoretical and experimental physicists. Recent developments in optical metamaterials promise an attractive approach towards perfect lenses using negative refraction to overcome the diffraction limit, improving resolution. However, those artificially engineered metamaterials are usually accompanied by high losses from...

Lenses from 100 gram albino rats remain clear and possess normal levels of Na+, K+, ATP, and hexokinase activity for 20 hours incubated in medium containing 12 mM glucose. Below 2.0 mM glucose, a cataract forms and there is an abrupt rise in lens Na+ and wet weight, a fall in lens K+, ATP, and hexokinase activity. The cataract is a thin lamellar opacity involving the anterior and posterior surf...

Conventional lens stops, implemented with an absorptive physical aperture, have an angle-dependent projection that introduces field dependent loss and reduces diffraction-limited resolution. Retro-telephoto lenses obtain uniform response using aberration vignetting, but this results in low wide-angle resolution and significant lens volume. However, an angle-independent "virtual" aperture can be...

The lens is derived from surface ectodermal cells which lie directly over the optic vesicle from which they are separated by the basement membranes and a thin interepithelial space. Early differentiation, folloicing induction, involves forming a compact disk of these epithelial cells in luhich the intercellular spaces have disappeared and their height increased. This disk or placode invaginates...

New ray-optical elements allow generalized refraction of light rays, but geometry imposes limitations on possible mappings between the positions of an object and its geometric image. Here I study the case of an infinite, planar, non-absorbing sheet that images the entire three-dimensional space. The most general case of such a sheet is equivalent to a thin lens with different objectand image-si...

PURPOSE To investigate thickness profile changes of the corneal epithelium and Bowman's layer at the vertical and horizontal meridians with overnight myopia orthokeratology (OK) lenses. METHODS Twenty subjects (age range: 19-33 years) wore reverse-geometry rigid gas-permeable OK lenses in both eyes for 30 days. Before lens wear and after 1, 7, and 30 days of overnight lens wear, evaluation of...

A novel atomic lens scheme is reported. A cylindrical lens potential was created by a large period (_~ 45 gm) standing light wave perpendicular to a beam of metastable He atoms. The lens aperture (25 gm) was centered in one antinode of the standing wave; the laser frequency was nearly resonant with the atomic transition 2381 23P2 ()~ = 1.083 gm) and the interaction time was significantly shorte...

Three-dimensional (3D) display has become an increasingly important technology trend for information display applications. Dozens of different 3D display solutions have been proposed. The autostereoscopic 3D display based on lenticular microlens array is a promising approach, and fast-switching microlens array enables this system to display both 3D and conventional 2D images. Here we report two...