PURPOSE Many contact lens (CL) manufacturers produce simultaneous-image lenses in which power varies either smoothly or discontinuously with zonal radius. We present in vitro measurements of some recent CLs and discuss how power profiles might be approximated in terms of nominal distance corrections, near additions, and on-eye visual performance. METHODS Fully hydrated soft, simultaneous-imag...

Most cataract surgery patients desire to not only enjoy excellent nonspectacle corrected distant vision, but also non-corrected near vision with glasses independence in this modern era. The implantation of accommodative IOLs may achieve this vision after cataract surgery according to the literature [2]. However, the price of the accommodative IOLs is about ten times more than the standard IOL. ...

PURPOSE Epidemiologic research has shown that multifocal spectacle wearers (bifocal and progressive addition lenses [PALs]) are more than twice as likely to fall than are nonmultifocal spectacle wearers, with this risk further increasing when negotiating stairs. The present study investigated whether step and stair descent safety is improved by using single-vision distance lenses. METHODS Fro...

The apodized diffractive multifocal intraocular lens is one of the intraocular lens types currently available for the correction of presbyopia. The design of apodized diffractive multifocal intraocular lenses improves on the visual outcomes obtained with the full optic diffractive and refractive intraocular lenses. In addition to the visual improvements, apodized diffractive multifocal intraocu...

Myopia affects up to one-third of the population in the United States today. It is a leading cause of low vision in Asian countries secondary to the increased risk of retinal detachments and glaucoma. Genetics, as well as environmental factors and nearwork have been hypothesized to play a role in myopia development. Current techniques to control its progression target these etiologies. Methods ...

The optical properties of crystalline lenses were studied in eleven species of coral reef fish from the Red Sea in Eilat, Israel. Three species each of diurnal planktivores, nocturnal planktivores and diurnal herbivores constituted three groups of animals with little within-group variability. In addition we studied two predators, which differed with respect to body size, prey preference, huntin...

We enjoyed reading the article by Esteve-Taboada et al.,1 but were disappointed by their interpretation of their data. Their optical model has important limitations that make it inappropriate to make broad clinical generalizations from their findings. First, the “aberration-free” eye model is highly artificial. In particular, the absence of any spherical aberration is relevant to only a small p...

The functional results (contrast sensitivity and dynamic visual acuity) of 19 multifocal (3M design) and 14 all polymethylmethacrylate biconvex monofocal intraocular lenses (IOLs), 6 mm in optical diameter were compared. Best corrected visual acuity was > or = 8/10 (Monoyer chart) Parinaud 2 in all cases. Major differences of functional performance in favour of monofocal IOLs were found outside...