In order to increase the water content and the oxygen permeability of hydrogels used in themanufacture of contact lenses, the polar monomer Silicon Hydrogel Contact Lenses (SHCL), and 2-hydroxyethyl methacrylate (HEMA) were copolymerized with the hydrogels. Due to the presence ofpolar monomers in the conventional contact lenses, the major component of the human tear,lysozyme is extensively adso...

This paper elaborates on analysis of progressive spectacle lenses, to correct presbyopia, which are nowadays offered at the market. The paper describes different types of progressive lenses, their parameters, length and width of their progressive segments. It also describes degressive spectacles lenses--progressive lenses on middle and near distance. The main part of the paper is a comparison o...

Six glycosidases were determined in: (1) lenses of alloxan-diabetic rats; (2) rabbit lenses incubated in high-glucose media in vitro; and (3) human senile cataracts, diabetic senile cataracts, and autopsy lenses. In diabetic rat lenses, the activities of /3-glucosaminidase, fi-galactosidase, and P-fucosidase increased with cataract progression as compared to control lenses. Glycosidase activiti...

this study compared tear function tests and cytologic changes on the conjunctival surface in asymptomatic patients wearing contact lens of different materials. included in this study were 40 eyes wearing daily wear 4 week replacement hydrogel (h) lenses, 32 eyes wearing silicone hydrogel (sih) lenses, 18 eyes wearing rigid gas-permeable (rgp) lenses, and 21 healthy eyes (no lenses) as the contr...

OBJECTIVES The impact of wearing lenses on visual and musculoskeletal complaints in VDU workers is currently unknown. The goal of this study was 1) to evaluate the impact of wearing VDU lenses on visual fatigue and self-reported neck pain and disability, compared to progressive lenses, and 2) to measure the effect of both lenses on head inclination and pressure pain thresholds during the perfor...

Lenses from young rhesus monkeys were incubated in the presence of H2O2 or oxygen radical generating systems to determine their suitability as a model for investigating lenticular oxidative stress. Additionally, direct comparisons were made between the effects found with the monkey lenses and those observed with cultured rat lenses exposed to the same oxidizing systems. As in earlier studies wi...

We describe a wink-controlled hands-free switching system for eye-borne telescopic vision, based on a previously tested fixed-magnification telescope embedded within scleral contact lenses. Here we integrate orthogonal polarizers into the contact lens covering the F/9.1 refractive 1× and F/9.6 catadioptric 2.8× vision paths, to allow switching via external liquid crystal shutters. We provide ha...

Purpose Cx46fs380 mice model a human autosomal-dominant cataract caused by a mutant lens connexin46, Cx46. Lenses from Cx46fs380 mice develop cataracts that are first observed at ∼2 months in homozygotes and at ≥4 months in heterozygotes. The present studies were conducted to determine whether Cx46fs380 mouse lenses exhibited abnormalities before there are detectable cataracts. Methods Lenses...

Background: Blindness due to cataract is a major and important problem in Pakistan. The problem is expected to increase in future due to increase in tobacco smoking. The aim of study was to look for the mechanism associated with metal deposition and its effect on antioxidant enzymes in lens of smokers in Karachi, Pakistan. Methods: 20 cataract patients were randomly selected from Out Patient De...

introduction: some fungi such as aspergillus, alternaria, cladosporium and fuzadium can peneterate matrix of contact lens. alternaria is a saprop and a pathogen in plants which is rarely seen in human being. this paper reported one case of contact lens contamination with alternaria in human. case report: the patient is a 24 year old woman who had used contact lens for 7 months. since she was on...