This paper clarified the microstructural element distribution and electrical conductivity changes of kaolin, fly ash, and slag geopolymer at 900 °C. The surface microstructure analysis showed the development in surface densification within the geopolymer when in contact with sintering temperature. It was found that the electrical conductivity was majorly influenced by the existence of the crystalline phase within the geopolymer sample. The highest electrical conductivity (8.3 × 10−4 Ωm−1) was delivered by slag geopolymer due to the crystalline mineral of gehlenite (3Ca2Al2SiO7). Using synchrotron radiation X-ray fluorescence, the high concentration Ca boundaries revealed the appearance of gehlenite crystallisation, which was believed to contribute to development of denser microstructure and electrical conductivity.

This paper presents the results of an investigation into the structure and properties of intraocular lenses (IOL) that are available on the ophthalmological market. The majority of implants of this type are based on acrylics or poly(methyl methacrylate) (PMMA). The acrylic lenses can be curled, which allows the making of just a minor incision during the associated implant surgery. The drawback of PMMA implants is their high rigidity, resulting in the need for a larger incision during the implant surgery. The benefits accrued from wearing such an implant are (1) the correction of focus for clear vision and (2) protection of the retina against UV-A radiation. X-ray diffractometry has confirmed the amorphous structure of all of the lenses investigated in this paper. The absorption and transmittance of the selected implants have been measured; differences found in the directional values of the transmittance and absorbance suggest the presence of differences in the implant coating (such as: different thickness or lack of coating on one side). It has been found that the PMMA-based implants exhibit the better properties with a level of light transmission in the visible spectrum of almost 40% and total protection against UV radiation. The acrylic implants feature lower transmittance in the visible light spectrum, and two of the investigated acrylic lenses failed to provide adequate protection against the UV radiation.

A retrospective analysis of parameters of vision and postoperative complaints in 428 patients (606 eyes) undergoing cataract surgery or clear lens extraction with ontime bifocal Oculentis® lens implantation.Artificial lens implantation was performed in one or in both eyes in patients without preoperative eye defect. Subsequent groups included patients with preoperative hyperopia, myopia and with corneal astigmatism. The biggest number of patients received spherical lenses with addition of 3.0 Dsph to near distances, then with addition of 1.5 Dsph, and toric lenses. The other two analyzed groups included patients who needed posterior vitrectomy and who have been preoperatively diagnosed with Age Related Macular Degeneration, dry and exudative changes. The main inclusion criterion was the need to become free of glasses to far and near distances. Almost all of patients obtained satisfactory visual acuity and quality of vision while maintaining the appropriate inclusion criteria. One of the criteria assumed that patients with larger pupil sizes were implanted with lenses with less addition to near distances, and corneal astigmatism was corrected even if the value was below 1 diopter.Highlights: Owing to their simple structure, intraocular bifocal lenses from Oculentis®, when certain qualification criteria are met, can replace monofocal lenses as the product of choice, giving measurable benefits including far and near vision without additional need for correction.

Oral steroid therapy was administered in three patients with skin symptoms, diagnosed with hands, mouth and foot disease (HMFD, commonly known as “Boston’s disease”) and in the course of which there was a rapid deterioration of vision in one eye. Each of the patients had previous contact with a person with disease. Hospitalization of the first patient, during which general antibiotic therapy, antiviral drugs and short-term intravenous steroid therapy were used, brought only a slight improvement in visual acuity. Given the accompanying colour discrimination dysfunction, oral steroid therapy was introduced in this patient, already in the outpatient setting. The therapy brought a significant improvement in visual acuity in a short time and restored the ability to distinguish colours. This form of treatment was used in another two patients with similar, good result.