Page 3 - Cahier-Matériaux-et-Traitements-GB.indd

Contents Contents Introduction p.5 1 Thinness and weight A Thinness p.6 1) Effect of the material’s refractive index 2) Effect of the aspherisation of the surfaces 3) Effect of surfacing on the thickness B Weight p.8 Plastic and glass materials FILES A Plastic materials p.9 1) Normal-index plastic materials 2) Mid-index plastic materials OPTICS 3) High- and very-high index plastic materials B Glass materials p.14 1) Standard glass materials 2) High-index glass materials Supplement: The principles of lens manufacturing p.15 OPHTHALMIC 2 Transparency and durability A Apparent colour of the material p.20 B Chromatism of the material p.21 C Anti-scratch treatments p.23 1) Principle of the anti-scratch coating 2) The anti-scratch coating process Supplement: Characterisation of the phenomenon of scratch-abrasion Historic evolution of anti-scratch treatments Measurement and control of anti-abrasion performance p.26 D Anti-reflective treatments 1) Different types of reflection and their effects p.28 Supplement: Visual benefits of anti-reflective treatments p.30 2) Principle of anti-reflective coating p.32 3) Specification and performances of anti-reflective coatings p.33 Supplement: The L*,a*,b* colorimetric sys tem ; bands of interference on the surfaces of high index lenses p.34 4) Manufacture of anti-reflective coatings p.36 E Anti-smudge and anti-dust treatments 1) Anti-smudge treatments p.37 2) Anti-dust treatments p.38 Supplement: Manufacturing technology of anti-reflective, anti-smudge and anti-dust treatments p.39 3 Copyright © 2010 ESSILOR ACADEMY EUROPE, 13 rue Moreau, 75012 Paris, France - All rights reserved – Do not copy or distribute.