Search

Contact lenses represent biomaterials whose main purpose is to correct the specific refractive anomaly of the eye. Since the visible light on its way to the perceptive part of the eye has to pass through the contact lens, the characteristics of the materials can significantly modify it. Biocompatibility of the lens surface is one of the most important issues in achieving contact lens wear without problems. We have developed new nanophotonic contact lens materials by adding nanoparticles of fullerene and their derivatives into standard PMMA RGP material. The aim of our investigation was to compare the influences of these materials on saline which is similar to tear film. We used NIR spectroscopy based on 12 vibration modes, called Aquaphotomics and Opto-magnetic imaging (OMI) spectroscopy as methods for characterizing the samples. The acquired spectrums were commented and compared with the standard contact lens material, which was analyzed by the same method.

UV/VIS spectroscopic characterization of glasses is a part of the standard procedure. The reasons to do it is to ensure UV eye protection and characterization of material transparency. However, we extend this research to IR domain because the quality of glasses depend not only on UV protection and their transparency but on complementarities and compatibility of eye vision with optical device, also. We characterized basic material of glasses by UV/VIS/NIR and novel method Opto-magnetic Imaging Spectroscopy (OMIS). Then we doped basic material with fullerenes, and characterized them using the same procedure. Results are presented and discussed.

The contact lens industry and market have displayed a high level of dynamism in the past few decades, and have evolved into a rapidly changing field in which science and everyday practice constantly interact. This work presents the comparative research of characteristics of the basic (commercial) material and nanophotonic materials which were obtained by incorporation of fullerene nanoparticles and its derivate in basic material for soft contact lenses. Basic contact lens material was sintetized of monomer 2-hydroxyethyl methacrylate (HEMA), and fullerene and its derivates were used due to their good transmission characteristics in ultraviolet, visible and near infra-red spectrum. For the purposes of characterization of materials for soft contact lenses Optomagnetic Spectroscopy (OMS) was used. OMS is based on difference between diffusely reflected white light and reflected polarized white light. This research contributes to applied optical science and biomedical application industry.

Electrical impedance measurement data and fractional calculus have been utilized for modeling bioimpedance properties of human skin. We introduced and proposed revisited Cole model using modified distributed order operator based on the Caputo-Weyl fractional derivatives. Our proposed model presents essentially modified single-dispersion Cole model, since it introduces a new parameters k and σ in single-dispersion Cole impedance equation. These parameters characterize the width of interval around fractional index α and they are important for more accurate describing bioimpedance properties of human skin. The impedance spectrum was measured in a finite frequency range up to 100 kHz. Our proposed modified Cole model fits much better to experimental curve in a given frequency range compared to existing Cole models. The fitting is done using the Levenberg-Marquardt nonlinear least squares.