Epithelial cell appearance and cell size were studied in intact, unfixed, and unstained human lenses. Ten normal and 24 cryoextracted senile or presenile cataractous lenses, all with subcapsular cataract, were examined. The cell size of the transparent normal lenses showed little variation. However, in the cataractous lenses, a wide range was found in mean cell size of different lenses and vari...

Contact lens correction of astigmatism is reviewed. According to literature data, rigid gas permeable lenses are the lenses of choice in correction of irregular and high astigmatism. The crucial advantage of rigid gas permeable lenses is clear vision and stable correction of astigmatism. Soft toric lenses ensure quick adaptation and comfort. The most prominent disadvantage of soft toric contact...

PURPOSE The purpose of this article is to evaluate patients' visual acuity, symptoms, and perceptions of vision-related quality of life in a randomized crossover clinical trial of overnight corneal reshaping (OCR) and daily wear soft lenses (SCL). METHODS Qualified subjects were randomly assigned to wear one mode of contact lens for 8 weeks and then, after a washout period, they wore the alte...

PURPOSE To evaluate the repeatability of power profiles measured on NIMO TR1504 (Lambda-X, Belgium) and investigate the effects of lens decentration on the power profiles for single vision (SV), bifocal (BF) and multifocal (MF) contact lenses. METHODS Accuracy of the sphere power was evaluated using single vision BK-7 calibration glass lenses of six minus and six plus powers. Three SV and fou...

A method has been developed whereby refractive microlenses can be produced in poly (methyl methacrylate) by excimer laser irradiation at λ = 248 nm. The lenses are formed by a combined photochemical and thermal process. The lenses are formed as depressions in the substrate material (negative focal length), which makes replication necessary in order to obtain lenses with a positive focal length....

OBJECTIVES To determine if a plano lens could be the test lens for all prescription (Rx) lenses and to investigate why Rx lenses pop out of safety eyewear. DESIGN Plano and Rx polycarbonate lenses (n = 641) with varying thickness and edge geometry, mounted on steel lens holders, and Rx safety eyewear (n = 128) placed on headforms were impacted with test objects of varying diameter and hardnes...

PURPOSE To investigate the efficacies of different concentrations of N-acetylcysteine (NAC) in preventing hyperoxia-induced lens opacification and changes to biochemical parameters in organ-cultured rabbit lenses. METHODS Thirty-six lenses from adult rabbits were divided into the control group (group A), the hyperoxia-exposed group (group B), and the hyperoxia-exposed, NAC-treated groups: 5 m...