Discover the most talked about and latest scientific content & concepts.

Concept: Lens


A 19-year-old man presented with a mass in his right eye that had been present since birth but had gradually increased in size. The mass caused vision defects, mild discomfort on blinking, and the intermittent sensation of the presence of a foreign body.

Concepts: Brain, Retina, Eye, Visual perception, Depth perception, Lens, Teratoma, Binocular vision


Biological materials are often based on simple constituents and grown by the principle of self-assembly under ambient conditions. In particular, biomineralization approaches exploit efficient pathways of inorganic material synthesis. There is still a large gap between the complexity of natural systems and the practical utilization of bioinspired formation mechanisms. Here we describe a simple self-assembly route leading to a CaCO(3) microlens array, somewhat reminiscent of the brittlestars' microlenses, with uniform size and focal length, by using a minimum number of components and equipment at ambient conditions. The formation mechanism of the amorphous CaCO(3) microlens arrays was elucidated by confocal Raman spectroscopic imaging to be a two-step growth process mediated by the organic surfactant. CaCO(3) microlens arrays are easy to fabricate, biocompatible and functional in amorphous or more stable crystalline forms. This shows that advanced optical materials can be generated by a simple mineral precipitation.

Concepts: Optics, Mineral, Solid, Calcium carbonate, Metaphysics, Lens, Glass, Microlens


To compare the performance of two novel multipurpose disinfecting solutions (MPDS) in preventing silicone hydrogel contact lens dehydration, provide higher scores of subjective comfort and stable optical quality during a month of lens wear in neophyte volunteers.

Concepts: Cornea, Myopia, Lens, Contact lens, Contact lenses, Corrective lens, Intraocular lens, Oxygen permeability


We present an overview of currently available toric intraocular lenses (IOLs) and multifocal toric IOLs. Relevant patient selection criteria, IOL calculation issues, and surgical techniques for IOL implantation are discussed. Clinical outcomes including uncorrected visual acuity, residual refractive astigmatism, and spectacle independency, which have been reported for both toric IOLs and multifocal toric IOLs, are reviewed. The incidence of misalignment, the most important complication of toric IOLs, is determined. Finally, future developments in the field of toric IOLs are discussed. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Concepts: Ophthalmology, Lens, Presbyopia, Contact lens, Refractive error, Intraocular lens, Cataract, Toric lens


PURPOSE: To investigate differences in ocular aberrations induced by centre-near multifocal soft contact lenses (SCL) relative to single vision SCLs and their effect on contrast sensitivity function (CSF). METHODS: Ocular aberrometry was measured in 18 cyclopleged subjects (19-24 years) while wearing Ciba Air Optix low (AOlow) and high (AOhigh) add, Bausch & Lomb PureVision low (PVlow) and high (PVhigh) add multifocals, and a Bausch & Lomb PureVision single vision (PVsv) control with the same -3.00D distance back vertex power. Zernike polynomials were scaled to 4, 5 and 6mm pupils. CSF was measured at equivalent distances of 6m, 1m and 40cm while fully corrected with spherical trial lenses at 6m. RESULTS: AOlow, AOhigh and PVhigh induced a negative shift in primary spherical aberration (Z12) from PVsv and all multifocal SCLs induced a positive shift in secondary spherical aberration (Z24) (all p<0.01), without significantly increasing coma. Area under the CSF (AUCSF) reduced at 40cm for all multifocals relative to PVsv (p<0.05), but was not significantly different at 6m or 1m. A moderate correlation (r=-0.80, p<0.005) was found between changes in Z12 and AUCSF at 40cm for AOhigh, with an increase in negative Z12 reducing multifocal-induced loss of CSF. CONCLUSIONS: Centre-near multifocal SCLs induced a negative shift in Z12 and a positive shift in Z24. Although CSF was unaffected at 6m and 1m it was reduced at 40cm, possibly because changes in Z12 and Z24 were not great enough to induce a significant shift in centre of focus and increase in depth of field.

Concepts: Optics, Redox, Lens, Contact lens, Keratitis, Bausch & Lomb


PURPOSE: To compare the visual outcomes of additional multifocal intraocular lenses (IOLs) for sulcus fixation with those of standard multifocal IOLs in the capsular bag. SETTING: Department of Ophthalmology, Rudolf-Virchow-Klinikum Glauchau, Glauchau, Germany. DESIGN: Prospective controlled clinical trial. METHODS: Eyes had phacoemulsification and implantation of a monofocal IOL in the capsular bag and an additional aberration-free diffractive IOL in the ciliary sulcus (multifocal add-on IOL group). Measurements of uncorrected and distance-corrected distance, intermediate, and near visual acuities; contrast sensitivity; and defocus curve were performed 3 months postoperatively. Results were compared with those in eyes with an aberration-correcting diffractive posterior chamber IOL (multifocal PC IOL group). RESULTS: The multifocal add-on IOL group comprised 34 eyes of 20 patients and the multifocal PC IOL group, 31 eyes of 17 patients. Cataract surgery, IOL implantation, and the postoperative course were uneventful in all cases. There were no statistically significant differences in uncorrected and distance-corrected distance, intermediate, or near visual acuities between the 2 groups. The median uncorrected distance visual acuity was 0.00 logMAR in both groups, and the median uncorrected near visual acuity was 0.10 logMAR in both groups. Contrast sensitivity testing yielded significantly better results in the multifocal add-on IOL group, especially at spatial frequencies over 1.5 cycles per degree. Defocus curves were similar in the 2 groups. CONCLUSION: Visual performance with a multifocal diffractive add-on IOL was equivalent to that achieved with a commonly used multifocal diffractive PC IOL. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Concepts: Statistical significance, Visual acuity, Ophthalmology, Lens, Contact lens, Intraocular lens, Eye surgery, Cataract


Lentil (Lens culinaris) is one of the cool season grain legume crops and an important source of dietary proteins and fibre. Fungal diseases are main constraints to lentil production and account for significant yield and quality losses. Lentil has a narrow genetic base presumably due to a bottleneck during domestication and as a result, any resistance to fungal diseases in the cultivated genepool is gradually eroded and overcome by pathogens. New sources of resistance have been identified in wild lentil (Lens ervoides). This article provides an overview of harnessing resistance potential of wild germplasm to enhance genetic resistance in lentil cultivars using next-generation sequencing-based genotyping, comparative genomics and marker-assisted selection breeding.

Concepts: Gene, Genetics, Genomics, Pulse, Fabaceae, Lens, Dietary fiber, Lentil


Suffering from giant size of objective lenses and infeasible manipulations of distant targets, telescopes could not seek helps from present super-resolution imaging, such as scanning near-field optical microscopy, perfect lens and stimulated emission depletion microscopy. In this paper, local light diffraction shrinkage associated with optical super-oscillatory phenomenon is proposed for real-time and optically restoring super-resolution imaging information in a telescope system. It is found that fine target features concealed in diffraction-limited optical images of a telescope could be observed in a small local field of view, benefiting from a relayed metasurface-based super-oscillatory imaging optics in which some local Fourier components beyond the cut-off frequency of telescope could be restored. As experimental examples, a minimal resolution to 0.55 of Rayleigh criterion is obtained, and imaging complex targets and large targets by superimposing multiple local fields of views are demonstrated as well. This investigation provides an access for real-time, incoherent and super-resolution telescopes without the manipulation of distant targets. More importantly, it gives counterintuitive evidence to the common knowledge that relayed optics could not deliver more imaging details than objective systems.

Concepts: Diffraction, Optics, Microscope, Wavelength, Lens, Telescope, F-number, Angular resolution


Focal adjustment and zooming are universal features of cameras and advanced optical systems. Such tuning is usually performed longitudinally along the optical axis by mechanical or electrical control of focal length. However, the recent advent of ultrathin planar lenses based on metasurfaces (metalenses), which opens the door to future drastic miniaturization of mobile devices such as cell phones and wearable displays, mandates fundamentally different forms of tuning based on lateral motion rather than longitudinal motion. Theory shows that the strain field of a metalens substrate can be directly mapped into the outgoing optical wavefront to achieve large diffraction-limited focal length tuning and control of aberrations. We demonstrate electrically tunable large-area metalenses controlled by artificial muscles capable of simultaneously performing focal length tuning (>100%) as well as on-the-fly astigmatism and image shift corrections, which until now were only possible in electron optics. The device thickness is only 30 μm. Our results demonstrate the possibility of future optical microscopes that fully operate electronically, as well as compact optical systems that use the principles of adaptive optics to correct many orders of aberrations simultaneously.

Concepts: Optics, Microscope, Lens, Photography, Wavefront, Focal length, Photographic lens, Depth of field


Recent advances in wearable electronics combined with wireless communications are essential to the realization of medical applications through health monitoring technologies. For example, a smart contact lens, which is capable of monitoring the physiological information of the eye and tear fluid, could provide real-time, noninvasive medical diagnostics. However, previous reports concerning the smart contact lens have indicated that opaque and brittle components have been used to enable the operation of the electronic device, and this could block the user’s vision and potentially damage the eye. In addition, the use of expensive and bulky equipment to measure signals from the contact lens sensors could interfere with the user’s external activities. Thus, we report an unconventional approach for the fabrication of a soft, smart contact lens in which glucose sensors, wireless power transfer circuits, and display pixels to visualize sensing signals in real time are fully integrated using transparent and stretchable nanostructures. The integration of this display into the smart lens eliminates the need for additional, bulky measurement equipment. This soft, smart contact lens can be transparent, providing a clear view by matching the refractive indices of its locally patterned areas. The resulting soft, smart contact lens provides real-time, wireless operation, and there are in vivo tests to monitor the glucose concentration in tears (suitable for determining the fasting glucose level in the tears of diabetic patients) and, simultaneously, to provide sensing results through the contact lens display.

Concepts: Eye, Cornea, Myopia, Lens, Contact lens, Corrective lens, Tears, Wireless energy transfer