In the developing vertebrate lens, epithelial cells differentiate into fiber cells, which are elongated and flat in shape and form a multilayered lens fiber core. In this study, we identified the zebrafish volvox (vov) mutant, which shows defects in lens fiber differentiation. In the vov mutant, lens epithelial cells fail to proliferate properly. Furthermore, differentiating lens fiber cells do...

We study the effect of the cosmological constant on the statistical properties of gravitational lenses in flat cosmologies (Ω0 + λ0 = 1). It is shown that some of the lens observables are strongly affected by the cosmological constant, especially in a low–density universe, and its existence might be inferred by a statistical study of the lenses. In particular, the optical depth of the lens dist...

A simple optical lens plays an important role for exploring the microscopic world in science and technology by refracting light with tailored spatially varying refractive indices. Recent advancements in nanotechnology enable novel lenses, such as, superlens and hyperlens, with sub-wavelength resolution capabilities by specially designed materials' refractive indices with meta-materials and tran...

A dielectric structure with effective permittivity and permeability close to -1 operating for propagative waves at optical wavelengths is proposed. This structure is a two-dimensional photonic crystal with refractive index -1, coated by appropriate antireflection gratings. Numerical simulations involving a flat lens made of this optimized crystal illustrate the improvements that antireflection ...

We derive a general theory for imaging by a flat lens without optical axis. We show that the condition for imaging requires a material having elliptic dispersion relations with negative group refraction. This medium is characterized by two intrinsic parameters sigma and kappa. Imaging can be achieved with both negative and positive wave vector refraction if sigma is a positive constant. The Ves...

Methods are developed to estimate the adhesion and surface free energies of compliant materials from the contact deformations of cylindrical lenses with flat sheets. Some important differences are found between the cylindrical contact studied here and the widely studied geometry of spherical contact. For example, while the pull-off force is completely independent of the elastic constants (K) of...

Coupling electron beams carrying information into electronic units is fundamental in microelectronics. This requires precision manipulation of electron beams through a coupler with a good focusing ability. In graphene, the focusing of wide electron beams has been successfully demonstrated by a circular p-n junction. However, it is not favorable for information coupling since the focal length is...

in view of the rapid expansion of contact lens amongst the users, new dimensions have been added to the domain of ophthalmology: giant papillay conjunctivitis, a disease caused by different kinds of contact lens, appears weeks or months after they are used, although some patients are struck years later. the predominant symptoms are increased awareness of lenses, ocular itching, blurred vision a...

We determine the coupling characteristics of a large mode area (LMA) photonic crystal, single-mode fiber when fed with an on-axis field lens used to place an image of the telescope exit pupil at the fiber input. The maximum field of view is found to be approximately the same as that of feeding the fiber directly with the telescope PSF in the image plane. However, the field lens feed can be used...

The Super View HTC Hassan Tornambe Disposable Contact Lens (Insight Instruments, Stuart, FL) is a disposable flat contact lens with a cellulose flange and four cellulose footplates. The circular lens is manufactured from high-index optical grade thermoplastic material, with a lens diameter of 13 mm and edge thickness of 4.8 mm (Figure 1A). The anterior surface is flat, whereas the concave poste...