We have investigated the focusing properties of surface plasmon polariton floating dielectric lenses. An analysis of the scattering characteristics of surface plasmon polaritons using a floating dielectric block shows that the air-gap thickness between a floating dielectric block and a metal substrate can be an effective dynamic variable for modulating the amplitude and phase of the transmissio...

PURPOSE To investigate the distribution of axial length, anterior chamber depth, lens thickness, vitreous chamber depth, and central corneal thickness in children at different age groups. METHODS We studied 364 eyes in 182 children with ages between 1 and 12 years. Axial length, anterior chamber depth, lens thickness, and vitreous chamber depth were measured by ultrasound biometry. Central co...

Objective To evaluate the reproducibility of in vivo crystalline lens measurements obtained by novel commercially available swept-source (SS) optical coherence tomography (OCT) specifically designed for anterior segment imaging. Methods and analysis One eye from each of 30 healthy subjects was randomly selected using the CASIA2 (Tomey, Nagoya, Japan) in two separate visits within a week. Each...

PURPOSE This study was performed to elucidate the correlation between added lens refill material and enhanced lens power as well as the correlation between lens refilling volume and accommodative amplitude as determined by equatorial stretching of ex vivo refilled pigs' lenses. METHODS Nine porcine lenses were refilled with increasing amounts of silicone oil. After each refill step, the lens ...

BACKGROUND To evaluate ocular biometric parameters in different subtypes of acute angle closure and compared to fellow eyes of AAC and PACS eyes. METHODS This is a retrospective chart review study. A total of 167 eyes (96 patients) consisting of 71 AAC eyes, 71 fellow eyes of AAC, and 25 PACS eyes were recruited. All patients underwent ocular examination and biometry. The mechanism of AAC was...

PURPOSE To measure interspecies thickness differences in the central anterior and posterior capsules of postmortem crystalline lenses, by a technique that maintains the anatomic integrity of the lens. METHODS Central capsule thickness was measured with a custom-built, noncontact optical system, using a focus detection technique. Anterior and posterior lens capsule thickness measurements were ...

PURPOSE To explore the possible influence of ocular growth, refractive error and age on the crystalline lens in school-age children. METHODS A Taiwan nationwide survey of myopia performed in 2006 was used to determine the prevalence and severity of myopia and the changes in ocular components. A total of 11,656 students were enrolled, including 5,390 boys and 6,266 girls, with ages ranging fro...

PURPOSE To quantify changes in crystalline lens curvature, thickness, equatorial diameter, surface area, and volume during accommodation using a novel two-dimensional magnetic resonance imaging (MRI) paradigm to generate a complete three-dimensional crystalline lens surface model. METHODS Nineteen volunteers, aged 19 to 30 years, were recruited. T(2)-weighted MRIs, optimized to show fluid-fil...

PURPOSE To study the changes in density and thickness in normal lenses related to aging, and to study changes in anterior chamber depth related to aging. METHODS Eighty nine normal volunteers (ages 9-80 yr) were examined and their eyes were photographed to obtain Scheimpflug photographs. The images were digitized and linear densitometry was performed, dividing the lens into five areas: poster...

INTRODUCTION Fresnel lenses are a type of lens that eliminates the bulk of a conventional lens by collapsing the lens thickness while retaining the curvature necessary for focusing. Figure 1 shows the Fresnel lens equivalent of a conventional lens. For a rotationally symmetric lens, the discontinuities or grooves formed when collapsing the lens are annular. This produces a much thinner lens, pa...