Ophthalmic lens coatings

Samson, Frank L.

doi:10.1016/0257-8972(95)02532-4

Cited by 82 publications

(45 citation statements)

References 13 publications

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“…The main limitation in using plastics for optical components (Samson 1996) is the softness of their surfaces, which is responsible for low impact and abrasion resistance. These materials are also porous in nature and can absorb water from the atmosphere and expand up to 2% of their volume, resulting in poor adhesion and even delamination of the coatings on their surfaces.…”

Section: Plastic Substrates Their Characteristics and Deposition Promentioning

confidence: 99%

“…The most commonly used plastic materials in the manufacture of plastic lenses for ophthalmic applications, like spectacle lenses, are CR39 and polycarbonate (PC), although polymethylmethacrylate (PMMA) is also gaining popularity (Samson 1996;Wikipedia 2006). CR39, specifically poly-diethyleneglycol bisallyl carbonate, is a plastic polymer commonly used in the manufacture of spectacle lenses.…”

Section: Plastic Substrates Their Characteristics and Deposition Promentioning

confidence: 99%

“…In the case of plastic substrates, the required energy is usually provided to the depositing material particles through ionassisted deposition processes-a fairly expensive although well-established technology (Pulker 1987(Pulker , 1999; Macleod *Author for correspondence (kmk_srivatsa@mail.nplindia.ernet.in) 2001; Baumeister 2004). Plasma polymerization processes enable the deposition of optical thin films at room temperature, at any rate below 100°C, and are therefore, especially suitable for plastic substrates (Samson 1996;Shi 1996;Martinu and Poitras 2000). In these processes, the ion energy can be controlled by altering the applied power and bias voltage.…”

Section: Introductionmentioning

confidence: 99%

“…In addition, since most plastic surfaces are hydrophobic, the surface of a plastic substrate has to be made 'wettable' so that the adhesion of the films to the substrate is improved, and a hard coating is required on the surface before the ARC is deposited on it (Samson 1996). Most of the processes in use today for depositing optical coatings like ARCs on plastic substrates are multistep processes: depositing a few nm thick layer of chromium which subsequently oxidizes to form a hard and adherent base layer (Samson 1996), spin-or dip-coating with acrylic resin solutions and curing thermally or by UV exposure (Hozumi et al 1996;Cerac 1997Cerac , 1998Cerac , 2000Fraunhofer 2001;Charitidis et al 2004a, b), followed by the deposition of the optical coating by ion-assisted physical vapour deposition or sputtering (Cerac 1998(Cerac , 2000. Ion implantation techniques (Bhattacharya 1998;Guzman et al 1998) and ion beam sputtering (Sarto et al 1999) have also been used to increase surface hardness and abrasion resistance.…”

Section: Introductionmentioning

confidence: 99%

“…The deposition of ARCs on glass lenses has been an extensively developed subject over several decades, but with plastic lenses increasingly replacing glass lenses in spectacles, the deposition of hard and durable ARCs on plastic lenses has become a very important technological activity over the past decade or so. The most widely used materials for plastic spectacle lenses are CR39 and polycarbonate (PC), as well as polymethyl methacrylate (PMMA) in some cases (Samson 1996;Wikipedia 2006). These plastic materials are not as brittle as glass and thus do not break easily, but they are relatively soft and can be easily scratched.…”

Section: Introductionmentioning

confidence: 99%

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Antireflection coatings on plastics deposited by plasma polymerization process

et al. 2008

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Abstract. Antireflection coatings (ARCs) are deposited on the surfaces of optical elements like spectacle lenses to increase light transmission and improve their performance. In the ophthalmic industry, plastic lenses are rapidly displacing glass lenses due to several advantageous features. However, the deposition of ARCs on plastic lenses is a challenging task, because the plastic surface needs treatment for adhesion improvement and surface hardening before depositing the ARC. This surface treatment is usually done in a multi-stage processexposure to energetic radiations, followed by deposition of a carbonyl hard coating by spin or dip coating processes, UV curing, etc. However, this treatment can also be done by plasma processes. Moreover, the plasma polymerization process allows deposition of optical films at room temperature, essential for plastics. The energetic ions in plasma processes provide similar effects as in ion assisted physical deposition processes to produce hard coatings, without requiring sophisticated ion sources. The plasma polymerization process is more economical than ion-assisted physical vapour deposition processes as regards equipment and source materials and is more cost-effective, enabling the surface treatment and deposition of the ARC in the same deposition system in a single run by varying the system parameters at each step. Since published results of the plasma polymerization processes developed abroad are rather sketchy and the techniques are mostly veiled in commercial secrecy, innovative and indigenous plasma-based techniques have been developed in this work for depositing the complete ARCs on plastic substrates.

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Section: Plastic Substrates Their Characteristics and Deposition Promentioning

confidence: 99%

Section: Plastic Substrates Their Characteristics and Deposition Promentioning

confidence: 99%