M.Tech. / The aim of this study was to determine whether Chiropractic cervical spine and/or upper thoracic adjustments had an effect on eye-hand co-ordination in asymptomatic participants presenting with cervical and/or upper thoracic spine dysfunction. Forty eight asymptomatic participants took part in this study. The participants were divided into three groups of sixteen participants each, each group consisting of eight male and eight female participants. Group 1 participants received Chiropractic adjustive therapy to dysfunctional segments in the C0-C3 spinal segments and C5-T1 spinal segments. In Group 2 the participants received Chiropractic spinal adjustive therapy to dysfunctional spinal segments in the C0-C3 region. Group 3 acted as the control group and participants received detuned ultrasound applied to the posterior cervical spine region. Two computer tests were involved in this study, namely the 2HAND test and the B19 test which had to be completed successively. The subjects were allowed to have a trial run each time they were tested to get a “hand’s-on feel” for the equipment. After the trial run the participants were tested, their respective treatment was carried out and the participants were then re-tested. Overall the study was able to show that Chiropractic adjustive therapy had no effect on eye-hand co-ordination in asymptomatic participants. Group 1 did not show any greater improvement in eye-hand co-ordination when compared to Group 2 where Group 1 received upper cervical spine and upper thoracic adjustments and Group 2 received only upper cervical adjustments. Gender was seen to play a significant role in the study, mainly during the B19 test. Overall it can be said that Chiropractic adjustive therapy had no effect on speed (OMD) or accuracy (OPED) during the test. Future research is needed on the possible effects of Chiropractic adjustive therapy on speed and accuracy as the study design showed some potential positive influences but may have been merely due to coincidence because of the small sample sizes. When testing eye-hand co-ordination it was noted that after the participants received Chiropractic adjustive therapy the length of mistakes in percent (LMP) decreased, meaning that the participants were able to correct any mistakes made at a faster rate after receiving Chiropractic adjustive therapy, but only when delivered to the spinal levels C0-C3 and/or C5-T1 (i.e. Group 1) for male participants only. Statistically significant results were noted when testing the number of mistakes made (NM) but only for male participants receiving Chiropractic adjustments to the C0-C3 levels only (i.e. Group 2). Future research needs to be done on the gender discrepancies noted for the different manner that Chiropractic adjustive therapy affected the different genders.

M.Phil. (Optometry) / Please refer to full text to view abstract

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We have a strong intuition that people's eyes are unique, socially informative stimuli. As such, it is reasonable to propose that humans have developed a fundamental tendency to preferentially attend to eyes in the environment. The empirical evidence to support this intuition is, however, remarkably thin. Over the course of eight chapters, the present thesis considers the area of social attention, and what special role (if any) the selection of eyes has in it. Chapters 2 and 3 demonstrate that when observers are shown complex natural scenes, they look at the eyes more frequently than any other region. This selection preference is enhanced when the social content and activity in the scene is high, and when the task is to report on the attentional states in the scene. Chapters 4 and 5 establish that the bias to select eyes extends to a variety of tasks, suggesting that it may be fundamental to human social attention. In addition, Chapter 5 shows that observers who are told that they will have to remember the scenes look more often at the eyes than observers who are unaware of the forthcoming memory test; moreover this difference between groups persists to scene recognition. Chapter 6 examines whether the preference for eyes can be explained by visual saliency. It cannot. Chapter 7 compares the selection of eyes to another socially communicative cue, the arrow. The results shed light on a recent controversy in the social attention field, and indicate again that there is a fundamental bias to select the eyes. Collectively the data suggest that for typically developing adults, eyes are rich, socially communicative stimuli that are preferentially attended to relative to other stimuli in the environment. / Arts, Faculty of / Psychology, Department of / Graduate

Toni Morrison's novel The Bluest Eye from 1970, shows how the upbringing and society's norms can affect a young girl in an African-American society, where racism and a feeling of inferiority is the standards. Pecola's wishes for blue eyes since that may make her part of a world where she has never belonged. Her wish is not only a futile attempt to be looking differently but also a wish for a better life.

The main Target is to compare commercial device for eye tracking analysis with a device made by DIY (Do it yourself) in the chosen environment. The work includes basic analysis methods Eye tracking. It offers a list of devices suitable for comparison, or marginally list of alternatives. A significant part of the thesis deals with construction of DIY tracker. The comparison is made on the basis of experimental measurements of commercial device and DIY device. The result is that in the selected conditions we can DIY device used because it is comparable with the commercial product. One of the sub-chapters is devoted also to question of the application DIY. In the last part was used the DIY device to analyse on realistic object. Specifically outdoor - print ads of Zubr brewery with evaluation.

An in vitro phagocytosis assay system was developed and characterized for studying the specific receptor-mediated phagocytosis of bovine ROS by bovine RPE cells. The phagocytosis of ROS was detected qualitatively by electron microscopy and quantitatively by treating RPE cells with radioiodinated ROS or by probing ROS-treated RPE cells with a radiolabeled antirhodopsin monoclonal antibody. The binding sites for various antirhodopsin monoclonal antibodies were localized as an essential step in their application as immunochemical probes for analysis of the structure and function of rhodopsin. Five monoclonal antibodies raised against rhodopsin have been shown to be directed against the N-terminal regions on the basis of their reactivity to an immunoaffinity purified 2-39 glycopeptide, a 2-16 tryptic glycopeptide and a 1-16 synthetic peptide as measured by radioimmune competition assays. Limited proteolysis, immunogold-dextran labeling and competitive inhibition studies identified two antirhodopsin monoclonal antibodies which bound to internal cytoplasmic loop regions of rhodopsin. Finally, the binding sites for these and other C-terminal specific antirhodopsin monoclonal antibodies were used to elucidate the proposed transmembrane helical model of rhodopsin. An antirhodopsin monoclonal antibody (rho 4D2), which bound to rhodopsin in glutaraldehyde-fixed ROS plasma membranes, was employed as an immunocytochemical probe in studying the possible role of rhodopsin in the binding and phagocytosis of rod outer segments. An immunoaffinity purified 2-39 N-terminal rhodopsin glycopeptide, a synthetic 1-16 peptide analogue of rhodopsin and phospholipid vesicles reconstituted with rhodopsin were all found to be ineffective in inhibiting the phagocytosis of ¹²⁵I-labeled ROS by RPE cells. In essence, these results provided compelling evidence that rhodopsin in the ROS plasma membrane does not function as the ligand for recognition by RPE cells. The molecular properties of the ROS cell surface ligand(s), which are involved in recognition by bovine RPE cells, were studied by limited-proteolytic digestion in conjunction with quantitative phagocytosis assays. Mildly trypsin-treated ROS were found to be less effectively phagocytized than untreated ROS by bovine RPE cells. Moreover, the glycopolypeptides (34kD and 24kD) released from the ROS cell surface by trypsin were capable of inhibiting ROS phagocytosis. The ROS plasma membrane specific, ricin-binding, 230kD glycoprotein was observed by SDS-gel electrophoresis and western blotting to be highly trypsin sensitive under these conditions. Hence, ricin affinity chromatography and immunoaffinity chromatography were employed in an attempt to purify this 230kD glycoprotein from ROS membranes. Enriched preparations of the 230kD glycoprotein were reconstituted into phospholipid vesicles and effectively used to inhibit the phagocytosis of ROS by RPE cells. In summary, a ROS plasma membrane specific, 230kD glycoprotein has been identified and isolated; this protein may act as a ligand in specific ligand-receptor interactions between ROS and RPE cells. / Medicine, Faculty of / Biochemistry and Molecular Biology, Department of / Graduate

M.Phil. / The primary purpose of this study was to investigate in different age groups the various relationships between autorefraction and subjective refraction, between autorefraction and retinoscopy and between retinoscopy and subjective refraction. Multivariate statistical methods are used to explore the nature of the relationships between these three different methods of evaluating refractive state. This is the first occasion in which these statistical approaches have been used to address these relationships within a sample of black South Africans. The short-term variation of measurements of the autorefractor used in this study was evaluated by means of an artificial or model eye. Here samples of fifty measurements each were obtained every two hours over a period of one day. Scatter plots, meridional profiles and hypothesis tests of equality of variance-covariance and of equality of mean autorefraction are used for analysis of the measurements obtained. Such analysis suggests that the variability in autorefraction across the day was of small magnitude and less than that typically found with human eyes. The implication is that many other factors besides the instrument itself are responsible for the variation found when using an autorefractor on a human eye. These factors include changes in accommodation, ocular fixation, the blinking process and attention. The environment within which the autorefractor is placed is important and changes in, for example, temperatur may have subtle but significant influences. The major part of this dissertation describes a study performed over a period of about seven months during which a sample of 240 male and female subjects were chosen randomly from a larger group of about 2800 patients who came to have their eyes examined in a clinical practice. A questionnaire was completed by each subject and retinoscopy was performed followed by subjective refraction and then autorefraction. Ocular health was assessed and visual acuities were measured. The study subjects were further divided into six smaller subgroups according to their ages and the analysis of results obtained with retinoscopy, subjective refraction and autorefraction included both qualitative and quantitative multivariate methods such as stereo-pair scatter plots, trajectories of change of dioptric power, meridional profiles, confidence and distribution ellipsoids, and testing of hypotheses of equality of variance-covariance and of equality of means. All of these methods help in understanding the nature of the various relationships between the different refractive methods, and they also are important when considering concepts such as mean refractive state and variation of refraction in human eyes. They also are used to develop an understanding of the distribution or spread of the population of refractive states from which the 'sample was obtained. For the three refractive methods . (retinoscopy, subjective refraction and autorefraction) the spread or distribution of measurements in the six age groups suggests that generally the refractive behaviour of right and left eyes was similar. A possible shift towards hyperopia and more astigmatism with increasing age is apparent. For example, mean autorefraction for the right and left eyes in the youngest and oldest age groups (Groups 1 and 6 respectively) is -0.41/-0.06 x 148 and -0.32/-0.07 x 177 and 0.41/-0.57 x 102 and 0.57/-0.32 x 75. Similarly mean subjective refraction for the right and left eyes of Group 1 is 0.10/-0.14 x 97 and 0.30/-0.17 x 81 and is 0.78/-0.70 x 95 and 0.89/-0.47 x 82 for the right and left eyes of Group 6 respectively. Again mean retinoscopy for the iv right and left eyes of Group 1 and Group 6 respectively is 0.69/-0.05 x 91 and 0.65/-0.21 x 82 and 1.72/-0.88 x 89

M.Sc. (Biochemistry) / Dry eye disease (DED) and keratoconus (KC) continue to affect the quality of life of many South Africans (and elsewhere) and in the case of KC often leads to blindness. It is estimated that DED affects 14% to 33% of the population worldwide, while 1 in 2000 of the worlds population is affected by KC. However, details of the etiology of these diseases and their biochemical ‘fingerprint’ remain uncertain. In this study, emphasis was placed on the investigation of immunological proteins in the precorneal tear film of DED and KC subjects and meibomian lipids in these individuals. Tear fluid and meibum were collected from control, DED and KC volunteers. Control subjects were non-contact lens wearers and free from ocular diseases, whereas DED subjects were diagnosed by means of an ocular surface disease index (OSDI) questionnaire. DED subjects were divided into two groups: ‘moderate DED’ and ‘severe DED’ based on OSDI. KC subjects were diagnosed by the use of a slit-lamp biomicroscopy exam. Enzymelinked immunosorbent assays were performed to quantitate secretory immunoglobulin A (sIgA), tumour necrosis factor-alpha (TNF-á) and matrix metalloproteinase-1 (MMP-1) in the collected tear fluid. Meibum was analysed with proton nuclear magnetic resonance (1H-NMR) spectroscopy and Fourier transform infrared spectroscopy (FTIR). Multivariate data analyses (PCA) were used to extract interpretable information from the multidimensional data generated from the aforementioned techniques and used to build a broad picture of the general lipidomic differences between DED, KC and healthy subjects. Tear levels of sIgA and MMP-1 were significantly decreased in patients with KC compared to control. In contrast, the tears of severe DED subjects were characterised by higher levels of TNF-á and lower levels of sIgA. In subjects with moderate DED, TNF-á levels were significantly elevated. The results of this study re-emphasize that KC and DED individuals are associated with differential expression of specific tear proteins and support the view that the severity of DED is reflected in the levels of immunological proteins present in basal tears. Differences in the chemical composition of meibum from subjects with severe DED and KC compared to control were observed, more specifically in the aliphatic region of 1H-NMR spectra and C-C rocking region of FTIR spectra. The results therefore point towards the saturated components of fatty acids (and their chemical environments) as key targets for future investigations to elucidate compositional differences between DED, KC and healthy meibum.

M.Phil. / Tinted spectacle lenses have long been worn to provide ocular protection from harmful electromagnetic radiation during recreational activities. Controversy exists surrounding the colour of the spectacle tints and the environmental conditions under which these tints are worn. There is little scientific evidence to substantiate the many opinions of authors on the effects of tinted spectacle lenses on visual skills and, ultimately, on overall performance in recreational situations. This study serves to provide scientific data concerning the effects of tinted lenses on static visual acuity, contrast sensitivity, colour vision, stereopsis and visual evoked potential (VEP). These results are related to the visible spectrum transmission curve for each experimental lens. recommendations are then made concerning the environmental conditions under which each lens tint should be worn. The HOYA ULT-2000 Light Transmission Metre was used to establish the percentage of visible light being transmitted through each of the experimental lenses. The DMS 80/90 Visible Spectrophotometer was used to generate a visible spectrum transmission curve for each of the 8 experimental lenses used in this study. 30 subjects (Group A) were randomly selected from the RAU student population for the assessment of the effects of tinted lenses static visual acuity, contrast sensitivity, colour vision and stereopsis. 10 students (Group B) were then randomly selected from the RAU student population for the assessment of the effects of tinted experimental lenses on visual evoked potential (VEP). The ametropic subjects in Groups A and B all wore their habitual spectacle or contact lens corrections throughout the testing procedure. The following lens tint colours were used: clear, black, grey, yellow, green, blue, red and pink. The subjects were evaluated binocularly without any tinted lens being worn, then through each of the 8 tinted experimental lenses (randomly presented). Results of the visual skills and VEP testing were analysed as follows: Group A: An average score was calculated for the results achieved on the static visual acuity, contrast sensitivity, colour vision and stereopsis tests when no experimental lenses were worn. This average was then compared to the average static visual acuity, contrast sensitivity, colour vision and stereopsis scores for each of the 8 experimental lenses. Group B: An average score was calculated for each of the amplitude and latency components of the VEP waveforms generated when no experimental lenses are worn. This average was then compared to the average amplitude and latency components generated when each of the 8 experimental lenses (as for Group A) are worn. Static visual acuity was assessed using a Snellen visual acuity letter chart at 6m. Contrast sensitivity was assessed using a Vistech VCTS 6500 Contrast Sensitivity Chart at 3m. Colour vision assessment was performed using the lshihara Colour Vision Test and the City University Colour Vision Test. The Random Dot Near Stereo Test was used to assess stereopsis. The Nicolet Pathfinder II was used to assess visual evoked potentials (VEPs). The results of this study show that the black, grey, yellow, green, blue, red and pink tinted lenses have a statistically significant influence on visual efficiency only when subjective methods (i.e. static visual acuity, contrast sensitivity, colour -vision and stereopsis) of visual efficiency assessment are used. The tinted lenses had little effect on visual efficiency when an objective means (i.e. VEP) of assessment was used, as there were no statistically significant differences between the lenses. The results of this research project indicate that the colour of the lens tint has little real effect on visual efficiency, when measured objectively. The effect of the lens tint is shown to be highly subjective. Tinted lens selection would therefore be based on personal preference and the amount of protection that the lens provides from harmful electromagnetic radiation. It can be concluded that no single lens tint is therefore suitable for all individuals under the same environmental conditions.