Plastic Spectacle Research Articles

Spectacle lens and contact lens recycling in South Africa

Background: The increase in global plastic waste generation poses a threat to human, animal and plant life. As such, industries world-wide are encouraged to review waste management systems to prevent, minimise, recycle or recover plastic waste. There is a paucity of information on plastic waste generation by the local optical industry in South Africa, especially with respect to spectacle lens and contact lens recycling.Aim: The purpose of this review article was to provide a current outlook on spectacle lens and contact lens recycling in South Africa.Methods: Literature review of scientific papers from online databases, websites and lens material patents.Results: No studies regarding lens recycling in South Africa were found. However, data for this review were collated based on lens constituent materials.Conclusion: This review article provided an overview of lens recycling, identified the barriers and potential measures to advance plastic spectacle lens and contact lens recycling in South Africa, and suggested controlled energy recovery as an alternative pending implementation of lens recycling programmes.Contribution: This paper contributes useful information on a previously unexplored aspect of recycling in South Africa. Ophthalmic lens recycling is currently not available in South Africa, and as such, this review focuses on the current outlook, barriers and considerations for implementation of such programmes.

Anaglyphic Three-Dimensional Movie: A Simple Binocular Method to Treat Anisometropic or Strabismic Amblyopia in Adults.

Purpose:To evaluate the efficacy of anaglyphic three-dimensional movies to treat adults with anisometropic or strabismic amblyopia.Methods:This is an interventional case series. The seven cases were put on a trial frame containing subjective refraction, fogging plus lenses for the dominant eye, correcting prism, and anaglyphic red-cyan plastic spectacles. Patients participated in 20 sessions of 1.5 h of anaglyphic three-dimensional animated movie watching in the office. Significant visual acuity (VA) improvement was defined as improvement ≥0.2 in logMAR values. Change in octaves of stereopsis was defined as halving the arcsec or 0.3 change in log arcsec.Results:The average age was 26.9 ± 10.0 (16–42) years. The mean VA in amblyopic eye improved significantly from 0.42 ± 0.19 (0.15–0.7) logMAR to 0.25 ± 0.15 (0.1–0.5) logMAR after completion of sessions (P = 0.02), and four cases showed significant VA improvement. The mean stereoacuity improved significantly from 2.6 ± 0.3 (2.1–2.9) log arcsec to 2.1 ± 0.5 (1.7–2.9) log arcsec (P = 0.04). Four cases showed ≥2 octaves improvements in stereopsis.Conclusion:A simple and readily available method of amblyopia treatment can be effective in some adult cases.

Allergic contact dermatitis from dyes used in the temple of spectacles.

We observed an increasing number of patients who presented with facial or retro-auricular dermatitis after skin contact with plastic spectacles or plastic covered temples. To identify the allergens in plastic spectacles that may cause allergic contact dermatitis. All patients with suspected allergic contact dermatitis to eyewear were tested with Solvent Orange 60 (SO60), four additionally with Solvent Yellow 14 (SY14), and five with scrapings from their own spectacles. In one case, a chemical analysis of the spectacles was performed to uncover the causative allergen. Three patients were allergic to SO60, two patients to SY14, and two patients were allergic to both SO60 and SY14. Patients with suspected allergic contact dermatitis from spectacles should be tested with SO60 and SY14, and based on findings from previous reports, also with Solvent Red 179.

Spectacle frames: Disposal practices, biodegradability and biocompatibility – A pilot study

Background: Only limited information is available on the disposal methods for spectacle frames, and their interaction with the environment once such disposal occurs.Aim: This study investigates the disposal of spectacle frames and provides a preliminary report on their biodegradability and biocompatibility.Setting: The study was conducted at a university in the south eastern part of South Africa.Methods: The study was conducted in two parts: Part A consisted of an explorative, quantitative design using a closed-ended questionnaire investigating the current disposal methods of 375 spectacle wearers for their old spectacles; and Part B consisted of a descriptive, cross-sectional design involving chemical analyses of metal and plastic spectacle frames.Results: Almost 55% of the participants reported either keeping or reusing their spectacles. Only 5% had used a recycling method when disposing their previous spectacles. Inductively coupled plasma optical emission spectroscopy results showed that metal frames do not degrade easily unless they are oxidised in an acidic environment. Lead was detected in two metal frames. Results of thermogravimetric analysis revealed that plastic frames only begin to degrade at temperatures over 250 °C. Gas chromatography-mass spectrometry results suggest that plastic frames, except three dimensional (3-D) polarisers, are biocompatible as they are stable, not chlorinated and do not possess heavy metals. The results suggested that eco-friendly frames may be the most biocompatible.Conclusion: It appears that few spectacle wearers use recycling for disposing their frames. Current metal and plastic spectacle frames appear to have poor biodegradability but good biocompatibility.

Nonfluorinated, transparent, and spontaneous self-healing superhydrophobic coatings enabled by supramolecular polymers

Transparent self-healing superhydrophobic coatings have important applications on lenses, solar cells, helmet visors, and windshields et al. However, their applications at the present stage are limited by hazardous fluorinated materials, low transmittance, and heating treatment for healing. In this study, nonfluorinated, transparent, and superhydrophobic coatings with spontaneous self-healing ability are successfully fabricated via spray coating an ethanol solution of polydimethylsiloxane (PDMS)-based supramolecular polymer cross-linked via N-coordinated boroxines (N-Boroxine-PDMS) and SiO2 nanoparticles. Benefiting from the use of spray-coating technique, the transparent self-healing superhydrophobic coatings can be readily applied to various substrates such as plastic spectacle lens, wood, metal, and paper, greatly expanding the scope of applications. The obtained coatings possess good transparency with a transmittance at 550 nm of 90.1% and excellent superhydrophobicity with a contact angle of 160.9° and a sliding angle of 1°, which can be attributed to the use of N-Boroxine-PDMS that is inherently transparent and hydrophobic. The N-Boroxine-PDMS/SiO2 coatings can withstand water impact, UV irradiation, and heating at elevated temperatures due to the use of N-Boroxine-PDMS. More importantly, the coatings are capable of repetitively and spontaneously healing the chemical damage caused by exposure to hydrogen peroxide or O2 plasma at room temperature because the reversibility of N-coordinated boroxines allows the oligomers of N-Boroxine-PDMS readily migrate to the damaged surface. Our finds show evidence that the use of properly designed supramolecular polymers as coating materials provides a simple and effective way to simultaneously integrate good transparency, stability, and spontaneous room-temperature self-healing ability in superhydrophobic coatings.

A Case of Allergic Contact Dermatitis due to Temple Tips of Plastic Spectacle Frames

A Case of Allergic Contact Dermatitis due to Temple Tips of Plastic Spectacle Frames

Spectacles and Embroidered Spectacle Cases from China in the Náprstek Museum

Abstract Spectacles from China appear in many museum collections, and they are popular collectibles in private collections. The collection of ten spectacles and their cases in the Náprstek Museum in Prague shows its technological and material development from the pince-nez type in the second half of the 19th century to early 20th century tortoiseshell and plastic spectacles. As signs of learning, these different types of spectacles and their cases show their social context and meaning in Chinese society during the transition period from the traditional to the modern era.

Allergic contact dermatitis from Solvent Orange 60 in spectacle frames

AbstractPotential allergens in plastic spectacle frames concern plasticizers, antioxidants, UV filters, and dyes. Among the latter, Solvent Orange 60 (SO 60) has been recognized as an important allergen, and presently 32 cases have been reported in Japan and Scandinavia. In Japan, the first case of allergic contact dermatitis (ACD) from SO 60 in spectacle frames was reported in 1999, and 17 similar cases followed until 2018. Since 2006, 14 cases, observed among plastic production workers, and spectacle and dental goggle users, were reported in Scandinavia. This review provides a summary of the 18 Japanese cases of ACD from SO 60, the clinical manifestations, diagnostic method and results, provenance of causative spectacle plastic plates, as well as some countermeasures to prevent contact allergy to it.

Solvent Orange 60 is a potent contact sensitizer in occupational and everyday life.

Solvent Orange (SO) 60 is a perinone-type dye that is often used in plastic materials such as spectacle frames and has been shown to cause contact allergy. The first case of SO 60 allergic contact dermatitis caused by spectacle frames was reported in 1999, and the second in 2011. We have recently seen 10 patients, of whom 6 developed dermatitis in the retroauricular/temporal area after wearing plastic spectacles. To report the cause of the dermatitis in the 10 patients and to describe our first case with occupational SO 60 contact allergy. In this retrospective study, patch test results of 10 patients, tested with the Swedish baseline series and our specific spectacle and/or plastic series, including SO 60 1.0% pet., in 2011-2017 were analysed. Ten patients, 2 males and 8 females, aged 43 to 71 years, reacted positively to SO 60 1.0% pet., namely, 4 pensioners, 2 nurses, 1 office worker, 1 teacher, 1 shop assistant, and 1 unemployed person. Four of the patients had an atopic history. Patch test reactions varied from + to +++; some had spread >20 cm outside the test area in terms of erythematous, infiltrated skin with papules. Retesting of patient no. 1 with serial dilutions of SO 60 in acetone showed positive reactions down to 1 ppm. Three patients reacted to the extracts of their earpieces. Gas chromatography-mass spectrometry was used to confirm the presence of SO 60 in 2 earpieces. SO 60 should be included in any spectacle patch test series that may be used. If there is a strong suspicion of contact allergy to SO 60 before patch testing, lowering the test concentration from 1.0% to 0.01% should be considered.

Modernity, Plastic Spectacle, and an Imperfect Utopia: A Critical Reflection on Plastic Paradise (1997) by Choi Jeonghwa

Plastic Paradise (1997), a massive yet precarious-looking vertical installation made of cheap, mass-produced industrial consumer goods found in popular places in Seoul, is one of a series of installations that South Korean artist Choi Jeonghwa (b. 1961) has produced since the mid-1990s. With architectonic metaphors that enact a uniquely self-reflective critique of Korean modern society and its ethos, this excessively vertical installation signifies the utopian hope of the Korean masses toward industrialization. However, its fragile material structure alludes to a counter-utopian reality latent in Korea's compressed growth (apch'uksŏngjang). This article provides a reading of the visual and tactile elements of Choi's art, which presents its unique structure as a cue for a nuanced social critique. Presenting samples of mass production as testaments to a modern utopia, Plastic Paradise critiques the pervasive myth within a society of mass consumption that these goods have become the totem of happiness "for all." Inspired by Choi's original observation of the dynamic form of the life of the masses, the installation also demonstrates how their seemingly mundane, everyday life is punctuated by the iconoclastic utopianism that they embrace for the future, and their understated creativity that continues to adapt and transform the given environment. In this way, the installation becomes both a monument and an antimonument to the state of development and its pervasive optimism.

The effects of plastic spectacles on the condition and behaviour of pheasants

Plastic spectacles are often fitted to pheasants in laying pens to reduce feather pecking and egg eating. This study examined the effects of spectacles on the physiological condition and behaviour...

Seeing for yourself: feasibility study towards valuing visual impairment using simulation spectacles

Elicitation of utilities from members of the public generally uses verbal description of health states. This paper reports the results of a small-scale time trade-off study on the feasibility of an alternative approach, where health states were simulated using plastic spectacles. This approach has methodological implications for the valuation exercise, in that many respondents find it difficult to conceive of visual impairment alone, without referring to their own current health. We conclude that it is feasible to simulate visual impairment in valuation exercises, but care must be taken to ensure what health state is effectively being valued.

Contact allergy to disperse dyes in plastic spectacle frames

Contact allergy to disperse dyes in plastic spectacle frames

Design of a rotary fast tool servo for ophthalmic lens fabrication

We have developed a novel fast tool servo and associated prototype diamond- turning machine for the production of plastic spectacle lenses. Our fast tool servo carries the cutting tool on a rotary arm and, thus, on a circular path, as opposed to straight line paths in conventional designs. The actuator, sensors, and bearings are standard elements that together allow experimentally demonstrated 500 m/s 2 instantaneous accelerations at the tool tip over a 3-cm range of cutting depth. We also describe in this paper new approaches we have developed for toolpath generation and calibration. The paper also presents associated control algorithms, because the controller must supply very high dynamic stiffness to the tool servo axis at multiples of the spindle frequency. This stiffness is achieved by means of repetitive control techniques. The new fast tool servo is shown to have great promise for machining asymmetric surfaces with large amplitude asymmetries.

ゾル‐ゲル法による膜形成とその機能 プラスチック眼鏡のハードコート膜

ゾル‐ゲル法による膜形成とその機能 プラスチック眼鏡のハードコート膜

A new set of fiducial markers for MRI, CT and SPET alignment.

A set of fiducial markers for use in the alignment of MR, CT and SPET images is presented. The marker system consists of individually produced imprints of the external auditory meatus, a pair of plastic spectacle frames and three fiducial markers. The markers are filled with a suitable contrast agent, fixed into the imprints and screwed onto the spectacle frame just before examination. The reproducibility in positioning the marker system on the patient was evaluated by repeated MRI examinations of a volunteer. The fiducial markers could be repositioned with an accuracy of less than +/- 1.6 mm in the left-right and anterio-posterior directions and +/- 1.9 mm in the cranio-caudal direction (95% confidence interval). The marker system is inexpensive and easy to produce, taking less than 20 min to produce on the ward. Only a few minutes are required to fix the system prior to examination. It is comfortable for the patient, even during long examinations. In cases lacking visible intrinsic structures and external contours, fiducial markers provide a good means of alignment for image fusion. The marker system described here for the alignment of SPET, CT and MR images can be used on a routine basis without the invasive fixation of fiducial markers.

Double-masked placebo-controlled trial of precision spectral filters in children who use coloured overlays

We selected 68 children who reported benefit from individually chosen sheets of coloured plastic placed upon the page when reading, and who used these regularly without prompting. These children viewed text illuminated by coloured light in an apparatus that allowed the separate manipulation of hue (colour) and saturation (depth of colour), at constant luminance. Many of the children reported improvements in perception when the light had a chromaticity within a limited range, which was different for each individual. A pair of plastic spectacle lenses (‘experimental’ lenses) was dyed so as to provide the appropriate chromaticity under conventional while (F3) fluorescent light. An additional pair was prepared having very similar colour but with a chromaticity outside the range in which perception was reported to improve (‘control’ lenses). Each pair was provided for 1 month in random order. The children kept diaries (36 completed) recording symptoms of eye-strain and headache. The children and those responsible for their assessment were unable reliably to distinguish ‘experimental’ from ‘control’ lenses. Nevertheless, symptoms were less frequent on days when the ‘experimental’ lenses were worn (P < 0.003).

Double‐masked placebo‐controlled trial of precision spectral filters in children who use coloured overlays

We selected 68 children who reported benefit from individually chosen sheets of coloured plastic placed upon the page when reading, and who used these regularly without prompting. These children viewed text illuminated by coloured light in an apparatus that allowed the separate manipulation of hue (colour) and saturation (depth of colour), at constant luminance. Many of the children reported improvements in perception when the light had a chromaticity within a limited range, which was different for each individual. A pair of plastic spectacle lenses ('experimental' lenses) was dyed so as to provide the appropriate chromaticity under conventional white (F3) fluorescent light. An additional pair was prepared having very similar colour but with a chromaticity outside the range in which perception was reported to improve ('control' lenses). Each pair was provided for 1 month in random order. The children kept diaries (36 completed) recording symptoms of eye-strain and headache. The children and those responsible for their assessment were unable reliably to distinguish 'experimental' from 'control' lenses. Nevertheless, symptoms were less frequent on days when the 'experimental' lenses were worn (P < 0.003).

New Options for Aniseikonia Correction: The Use of High Index Materials

The increased popularity of refractive surgery, intraocular lenses, and penetrating keratoplasty has resulted in larger numbers of anisometropes with aniseikonia. We have analyzed the effects of the new high index glass and plastic spectacle lens materials on the design of eikonic lenses sometimes used for these patients. Our results demonstrate that high index materials allow thinner and flatter lens designs. Thus, higher levels of aniseikonia correction and improved cosmetic appearance of eikonic spectacle lenses can be achieved. We present shape magnification nomographs that facilitate eikonic lens design with these materials.

The effect of prescription eyewear on ocular exposure to ultraviolet radiation.

Several studies have suggested that ultraviolet radiation in sunlight may cause cataracts and other eye disease. We evaluated the effect of prescription eyewear in attenuating ocular exposure to ultraviolet radiation (UVR) in the sunlight portions of the ultraviolet spectrum (295-350 nm). Using natural sunlight as the source, the attenuation was measured with two ultraviolet detectors, one sensitive to only UVB (295-315 nm) and one sensitive to both UVA and UVB (295-350 nm). A random sample of spectacles, spectacle lenses, and contact lenses was examined. The average transmission, as measured with either detector, was highest for soft contact lenses, followed by glass spectacle lenses, untinted hard contact lenses, and plastic spectacle lenses. Measurements performed with mannikins wearing spectacles showed that an average of 6.6 per cent of incident radiation reached the eye even when the lenses were covered with black opaque tape. The amount of exposure was increased substantially when the spectacles were moved 0.6 cm away from the forehead. The results show that the protection against ultraviolet exposure provided by prescription eyewear is highly variable and depends largely on its composition, size, and wearing position.