Cataract, the opacification of eye lens, is the leading cause of blindness worldwide. At present, the only remedy is surgical removal of the cataractous lens and substitution with a lens made of synthetic polymers. However, besides significant costs of operation and possible complications, an artificial lens just does not have the overall optical qualities of a normal one. Hence it remains a si...

purpose: to describe the biometric changes and their effect on intraocular lens (iol) power calculation after trabeculectomy and to compare the accuracy of four formulas namely srk/ii, srk/t, holladay and hoffer q for iol power calculation in these patients. methods: thirty-four eyes of 31 glaucoma patients who were scheduled for primary trabeculectomy were enrolled. a non-contact biometry devi...

purpose: to evaluate the safety, efficacy, stability and predictability of posterior chamber collagen copolymer phakic intraocular lens (piol) implantation to correct myopia and myopic astigmatism in keratoconus-affected patients. methods: uncorrected (ucva) and best-corrected (bcva) distance visual acuity, refraction and complications were evaluated in 22 keratoconic eyes of 14 patients who un...

purpose: to compare visual outcomes and surgical complications of three phakic intraocular lenses (piols); artisan, artiflex and the implantable collamer lens (icl) for correction of moderate to high myopia. methods: in this historical cohort study, 112 myopic eyes that were operated between 2005 and 2010 and implanted with one of these three piols were evaluated (artisan 40 eyes, artiflex 36 e...

background: silicon hydrogel bandage contact lenses are used to enhance epithelial healing, control surface-generated pain, and prevent epithelial erosions after refractive surgery. considering the importance of faster reepithelialization in preventing complications of photorefractive keratectomy (prk) and the fact that the features and specifications of these commercially-available lenses are ...

Gravitational lensing represents a powerful tool to estimate the cosmological parameters and the distribution of dark matter. I will describe the main observable quantities, concentrating on strong lensing, that manifests its effect through the formation of spectacular events, like multiple quasars, Einstein rings and arcs in clusters of galaxies. In events where a quasar is lensed by an interv...

Microfluidic systems based on fluorescence detection have been developed and applied for many biological and chemical applications. Because of the tiny amount of sample in the system; the induced fluorescence can be weak. Therefore, most microfluidic systems deploy multiple optical components or sophisticated equipment to enhance the efficiency of fluorescence detection. However, these strategi...

Cataract, the opacification of eye lens, is the leading cause of blindness worldwide. At present, the only remedy is surgical removal of the cataractous lens and substitution with a lens made of synthetic polymers. However, besides significant costs of operation and possible complications, an artificial lens just does not have the overall optical qualities of a normal one. Hence it remains a si...

A new class of gradient refractive index (GRIN) lens is introduced and analyzed. The interior iso-indicial contours mimic the external shape of the lens, which leads to an invariant geometry of the GRIN structure. The lens model employs a conventional surface representation using a coincoid of revolution with a higher-order aspheric term. This model has a unique feature, namely, it allows analy...

Recent genetic studies show that the Eph/ephrin bidirectional signaling pathway is associated with both congenital and age-related cataracts in mice and humans. We have investigated the molecular mechanisms of cataractogenesis and the roles of ephrin-A5 and EphA2 in the lens. Ephrin-A5 knockout ⁻/⁻ mice often display anterior polar cataracts while EphA2⁻/⁻ lenses show very mild cortical or nucl...