الفهرس 
Introduction
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Abstract
Importance: Contact lenses, used in correction of vision problems, have advantages and disadvantages. Purpose: Survey studies on structural, physical and environmental properties of contact lenses materials collected from Dakahlia Governorant. Method: 1. Studying Structural properties, which investigated by: Xray diffraction, UV and IR spectrometer. 2. Studying Physical Properties of contact lenses such as Hardness, Refractive index. 3. Studying Environmental effects, these include deposits on contact lenses. Such as Minerals (Calcium and Magnesium), Proteins, Bacteria and fungi. Results and Conclusion: ?The xray diffraction pattern of contact lenses is relatively unstructured; this pattern is a typical one of the amorphous state. The structural changes of the used contact lenses material may be due to the biomedical, physical structure or the dynamic state of the tear film. The refractive index is increased due to the existence of Ca and Mg in between molecular chain and decreases as the water content in the contact lenses material increase. The surfaces of all worn lenses are strikingly different from those of never worn lenses; the worn lenses are covered with deposits. The pure unused contact lenses show clear three UV bands, indicating the presence of active groups in the contact lenses. No bands are shown in case of visible region of spectra, showing the absence of any color absorbing pigment in the contact lenses. It is apparent from this work that the problem of describing an ideal material is an impossible one. The results confirmed that the increase of the contact lenses wearing period is not only deposition parameter enhancing the depositions, but the lens care and the environmental can strongly affect the rate of depositions.