PURPOSE The aim of the study was to comparatively analyze crystallin fragments in the water soluble high molecular weight (WS-HMW) and in the water insoluble (WI) protein fractions of human cataractous (with nuclear opacity) and age matched normal lenses to determine the identity of crystallin species that show cataract specific changes such as truncation and post-translational modifications. B...

AIMS The corneal epithelial permeability during extended wear of disposable contact lenses was compared with that during daily wear of soft contact lenses. The study was performed to verify whether the extended wear of disposable contact lenses would result in a higher permeability value than the daily wear of soft contact lenses. A higher permeability makes the cornea more vulnerable for bacte...

PURPOSE Soft contact lenses with spherical base curves have been used for many years. The computation of the refractive powers of these lenses is easy, requiring only that one uses the lens maker equation for thick lenses. Nevertheless, for customized contact lenses, there is yet no reliable method for measuring the higher order optical aberrations. In this study we have developed in the Center...

To obtain information about the effects of lenticular polyols on the prevention, initial stages, and development of diabetic cataracts, we identified and determined with gas-liquid chromatography or gas-liquid chromatography/mass spectrometry eight polyols in cataractous lenses of non-insulin-dependent diabetes mellitus patients and nondiabetic subjects. In the diabetics' lenses, the concentrat...

The purpose of this study was to clarify the effects of colored lenses on the visual performance of middle-aged people. The subjects were 19 middle-aged people with a mean age of 57.4 ±6.0 years. Five different functional lenses were used in the experiments: colorless lenses and four colored lenses (Light-yellow, Dark-yellow, Light-gray, and Dark-gray). Using each lens type, contrast sensitivit...

PURPOSE Evaluate contact lenses fitting after intracorneal ring implantation for keratoconus, its visual acuity and comfort. METHODS Retrospective study of patients undergoing contact lenses fitting, after intracorneal ring for keratoconus. The criterion for contact lens fitting was unsatisfactory visual acuity with spectacle correction as referred by the patients. All patients were intoleran...

AIM To determine the effect of pH, osmolality, and buffering system on the oxygen permeability (Dk) of soft contact lenses. METHODS Two hydrogel lenses (nelfilcon A and etafilcon A) and 2 silicone hydrogel lenses (lotrafilcon A and balafilcon A) were used in the study. These lenses were incubated in phosphate-buffered saline (PBS) and borate-buffered saline (BBS) solutions adjusted by 0.8 pH ...

In many cases of heavy earthquakes, liquefaction has resulted in serious damages. Existing anisotropy in soil layers results  in some difficulties to realize the reason for these phenomena. Loose sand lenses buried in fine soils are one of the cases which may result in these problems and as a weak point during the earthquake can cause this phenomenon. In this paper, using FLAC 2D software, doub...

PURPOSE To quantify and compare the in vitro adherence of Staphylococcus epidermidis and Pseudomonas alcaligenes to different intraocular lenses (IOLs). METHODS Fourteen intraocular lenses were used in the experiment. Four of polymethylmethacrylate (PMMA), four of silicone, four of hydrogel and two of acrylic. Eight intraocular lenses were placed in eight test tubes containing 4 ml of Pseudom...

This study was undertaken to determine the effects of thin (60 microns) and thick (240 microns) soft contact lenses of equal water content (70%) and power on nonlesioned and lesioned rabbit corneas. In one group of animals, corneas were not lesioned. Thin lenses were placed on left corneas and thick lenses on right corneas. In a second group, lesions were made in both corneas. Left corneas were...