Scratch resistance of rigid contact lens materials

Tranoudis, Ioannis & Efron, Nathan (1996) Scratch resistance of rigid contact lens materials. Ophthalmic and Physiological Optics, 16(4), pp. 303-309.

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Practitioners have long recognised the importance of determining the extent of scratching on the surface of rigid contact lenses when deciding on lens replacement. Despite this, little research has been undertaken to define this problem. The extent of scratching of rigid contact lens materials was evaluated and this property was related to material oxygen permeability and refractive index. One hundred and forty lenses made from 28 different rigid materials were evaluated in a masked and randomised manner. Scratches were created on the front surface of the lenses using an apparatus that was specifically designed and constructed for this experiment. The extent of scratching was quantitatively evaluated using a computer-based scanning and image analysis system. The oxygen permeability of all materials was measured using the polarographic method. An Atago N3000 hand-held refractometer was used to measure the refractive index of these materials. Three significant correlations were revealed: an inverse relationship (r = -0.813, P < 0.0001) between oxygen permeability and refractive index; a positive relationship (r = 0.511, P < 0.008) between oxygen permeability and the extent of scratching; and an inverse relationship (r = -0.539, P < 0.0058) between refractive index and the extent of scratching. The information generated in this study concerning scratch resistance of rigid contact-lens materials may assist the contact lens industry and contact lens practitioners in developing and prescribing rigid lenses with optimal performance characteristics.

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10 citations in Scopus
3 citations in Web of Science®
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ID Code: 3387
Item Type: Journal Article
Refereed: Yes
Additional Information: For more information, please refer to the journal’s website (see link) or contact the author. Author contact details:
Keywords: Contact Lenses, Equipment Design, Hardness, Optics, Oxygen, Permeability, Research Support, Non, U, S, Gov't
DOI: 10.1046/j.1475-1313.1996.95001212.x
ISSN: 0275-5408
Subjects: Australian and New Zealand Standard Research Classification > MEDICAL AND HEALTH SCIENCES (110000) > OPTOMETRY AND OPHTHALMOLOGY (111300)
Divisions: Current > QUT Faculties and Divisions > Faculty of Health
Current > Institutes > Institute of Health and Biomedical Innovation
Copyright Owner: Copyright 1996 Blackwell Publishing
Copyright Statement: The definitive version is available at
Deposited On: 10 Feb 2006 00:00
Last Modified: 10 Aug 2011 17:55

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