High Refractive Index Plastic Optical Materials

Abstract

[Master of Philosophy thesis]. Although, glass was the only lens material for over 600 years, today plastic lenses used for prescription eyewear and sunglasses requiring high abrasion resistance and high quality optical properties have been developed. These first plastic lenses, like CR-39" with a 1.498 refractive index, could not compete with the high index glasses known as flints. High index plastic lenses are a new lens category, having refractive index from 1.54 (SOLA Spectralite) to even thinner 1.71 high index (Hoya Teslalide). Recently, much interest has been shown in development of new high index polymeric materials. Main target of all these efforts of course is the production of lenses with a very good optical performance. This performance includes high refractive index, low constrigence, good light transmission and UV absorption. Obviously, the outstanding factors defining this performance are refractive index and chromatic aberration. The refractive index can easily be measured using a light source or a laser beam and computing the minimum deviation angle after the beam refraction through a prism of the material. The chromatic aberration can be determined by evaluating the optical performance of the material itself. Nowadays, ophthalmic lenses of plastic have become very popular because they are inexpensive, lighter in weight and more resistant to shattering than glass. However plastic lenses generally have less surface hardness and wear resistance, especially materials such as polycarbonate, polyethylmethacrylate, and polyallyldiglycol carbonate which have to be improved by surface coatings and processes such as hard-coating. At all times we have to consider that spectacle lenses have a psychological function. In that way, what is better for the consumer is not always what is best for the researcher. In order to check out this factor, is essential to look into the performance of these plastic materials in front of the consumer's eye. Experimental work included testing and estimating refractive index and chromatic performance of various plastic lenses. On one hand, we had to verify and confirm the index of new materials in ophthalmic lenses market and on the other hand to compare different plastic materials about the chromatic dispersion, transparency and yellowness.

Publication DOI: https://doi.org/10.48780/publications.aston.ac.uk.00021763
Divisions: College of Health & Life Sciences > School of Optometry > Optometry
Additional Information: Copyright © Aris V. Chandrinos, 2003. Aris V. Chandrinos asserts their moral right to be identified as the author of this thesis. This copy of the thesis has been supplied on condition that anyone who consults it is understood to recognise that its copyright rests with its author and that no quotation from the thesis and no information derived from it may be published without appropriate permission or acknowledgement. If you have discovered material in Aston Publications Explorer which is unlawful e.g. breaches copyright, (either yours or that of a third party) or any other law, including but not limited to those relating to patent, trademark, confidentiality, data protection, obscenity, defamation, libel, then please read our Takedown Policy and contact the service immediately.
Institution: Aston University
Uncontrolled Keywords: Plastic lenses,high index,Abbe value,minimum deviation angle,optical performance
Last Modified: 15 Dec 2023 17:22
Date Deposited: 19 Mar 2014 17:40
Completed Date: 2003-05
Authors: Chandrinos, Aris V.

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