INTERFERENCE SPECTRA IN THE VISIBLE REGION OF TRANSPARENT COATINGS APPLIED TO PLASTIC INDUSTRIAL LENSES

The effects of geometry of lenses on the determination of thickness of transparent protective coatings applied to ophtalmic lenses by the interference visible spectra analysis were investigated. The obtained results suggest that, although the thickness of protective coatings is similar ( on the order of 3-5 mum), the definition of interference fringes decreases with increasing absolute value of spherical power ( measured in diopters ); nevertheless, interference visible spectra allow the accurate measurement of thickness of thin transparent layers applied to surface of ophtalmic lenses.