Catalogue Number: 3965 Rigid Contact Lenses in Flat 'Mailer' Case Category: Spectacles and lenses Sub-Category: Contact lenses and accessories Year Of Publication/Manufacture: 1980s Time Period: 1940 to 1999 Place Of Publication/Manufacture: Melbourne Description Of Item: White flat 'mailer' case 42 mm x 38 mm x 8 mm embossed L and R on the face with labels adhered to the back containing lens parameters for the grey tinted PMMA material left lens and blue tinted Polycon HDK material right lens contained in the respective compartments. Right lens power -4.50 and left lens power +12.50. Historical Significance: PMMA (Poly methyl methacrylate acrylate) a material of Dk 0 and refractive index1.429 was the original plastic used for the manufacture of contact lenses. It has been superseded in most cases by gas permeable materials.Polycon HDK is a silicone acrylate material of Dk 50 and refractive index1.465 produced by Syntex who began their development of contact lens materials in 1980. Polycon HDK was a developed later. How Acquired: Donated by Colin Bates Date Acquired: 20/11/2017 Condition: Good Location: Archive Office. Cabinet One Drawer 16 |