AIM Although 1 week of continuous wearing time (CWT) is recommended for extended wear soft contact lenses (EWSCL), there have been few studies concerning the appropriateness of this or other CWTs. The current study was undertaken to examine the effect of various CWTs on the cornea by observing the corneal epithelium. METHODS Specular microscopy was used to evaluate corneal epithelial changes ...

PURPOSE To study the deformation response of three distinct contact lenses with known structures, which served as corneal models, under different chamber pressures using ultra-high-speed (UHS) Scheimpflug imaging. METHODS Three hydrophilic contact lenses were mounted on a sealed water chamber with precisely adjustable pressure: TAN-G5X (41% hydroxyethylmethacrylate/glycolmethacrylate, 550 µm ...

Purpose. To investigate the effect of tear protein deposition on the change in oxygen permeability (Dk) of soft contact lenses (SCL). Methods. Three hydrogel lenses (polymacon, nelfilcon A, and etafilcon A) and two silicon hydrogel lenses (lotrafilcon A and balafilcon A) were investigated. Etafilcon A lenses were incubated in artificial tear solution for 1, 6, 12, and 48 h, whereas the other SC...

To investigate the lubrication on different soft contact lenses during a week of wearing them. Twenty-five subjects participated in this research for six weeks and they wore six different soft contact lenses (Pure Vision B&L, Pure Vision II B&L, Air Optix, Focus N&D CIBA, Biofinity Cooper, Acuvue Oasys J&J). The contact lenses were randomly selected and the subjects did not know which contact l...

PURPOSE To evaluate the impact of disposable soft contact lenses upon visual performance by comparing the optical aberrations of myopic eyes with and without the use of contact lenses. METHOD The optical aberrations of a set of 18 eyes were measured by a laser ray tracing system, an objective measurement method, enabling comparison of the findings of the naked eye, the eye plus a test lens, a...

Clinical studies were conducted on 466 patients waiting for senile cataract surgery and receiving chloromycetin, gentamicin, or carbenicillin subconjunctivally and through New Sauflon 70 and New Sauflon 85 lenses. The aqueous drug levels were biologically estimated at various time intervals. Soft contact lenses provided significantly higher drug penetration than subconjunctival therapy. Both mo...

PURPOSE The aim of this study was to analyze surface changes of three silicone-hydrogel contact lenses after daily wear. The lenses used in this study were balafilcon A, lotrafilcon B (both surface-treated), and galyfilcon A (non surface-treated). METHODS To understand how and where proteins, lipids, and other contaminants change contact lenses, surface roughness was assessed through Atomic F...

Introduction Hydroxyethylmethacrylate (HEMA) is a hydrop~ylic absorpt1ve hydrogel of good mechanical strength which can, in the dehydrated state, he la;the cut to accura'te dimensioIlls and then rehydrated to form a softconta,et Jens of excellent optical properties. Lenses intended for correction .of ametropia (usually myopia) have a water content of 30 per cent to 40 percent hut the ma:terial ...

Within a few minutes of wear, contact lenses become rapidly coated with a variety of tear film components, including proteins, lipids, and mucins. Tears have a rich and complex composition, allowing a wide range of interactions and competitive processes, with the first event observed at the interface between a contact lens and tear fluid being protein adsorption. Protein adsorption on hydrogel ...

The frictional property of soft contact lenses could have a great impact on their clinical performance. However, to date, only a handful of studies have been conducted to understand the friction mechanism(s) of the soft contact lens. In the current paper, the friction of senofilcon-A contact lenses has been studied with a stainless steel ball as the counterface in a saline solution. The load ap...