published_or_final_version / Industrial and Manufacturing Systems Engineering / Doctoral / Doctor of Philosophy

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Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1976. / Bibliography: leaves 113-121. / Microfiche. / vii, 121 leaves ill. 29 cm

M.Phil. / Sports vision has been a part of sport for a long time, probably since an athlete was first told to: ‘keep his eye on the ball’. It is only recently that athletes are beginning to realize the advantages of using their eyes to their full potential, and the difference it can make in an athlete’s performance. This is more prevalent today, where athletes can become instant hero’s and earn huge salaries. For a number of years specific instruments were used to test specific visual skills and norms were calculated for these skills. A few questions arises though when the norms for these visual skills are carefully studied. The purpose of this study was to evaluate previous norms and to develop norms and protocols for sports vision evaluations. Various visual skills were examined and previously used results evaluated. Key performance indicators in the evaluation of an athletes, as well as the cornerstones of sport vision were also discussed. Only elite athletes were used in this study. / Prof. J.T. Ferreira

The problem of this study was to ascertain the effects of selected color phenomena upon the identification and comparison of color by college students. Instruments used for this study were the Snellen Visual Acuity Chart, which measures crudely the the binocular visual activity of an individual; Pseudo-Isochromatic Plates for Testing Color Perception, which roughly determine red-green color deficiency; and the "Isoline Color Phenomena Perception Presentation," which determines how an individual identifies or compares selected color phenomena.

No / PURPOSE. Potential vision testing attempts to predict the visual outcome that might be expected as a result of a cataract operation. This report details the clinical utility of critical flicker frequency (CFF) as a potential vision test (PVT). METHODS. CFF thresholds were determined in 31 subjects with age-related idiopathic cataract and no other eye disease, 19 subjects with macular disease (MD) and clear ocular media, and 24 age-matched control subjects. In addition, the CFF technique was administered before cataract surgery in 52 patients and compared with the information provided by presurgical case history and ocular examination alone (ophthalmological judgment [OJ]) and results from two commonly used PVTs (the retroilluminated pinhole and the potential acuity meter). RESULTS. CFF thresholds obtained in the nonsurgical cataract group were unrelated to cataract severity and were similar to those in the control group. In contrast, CFF scores were significantly related to visual acuity (VA) in the MD group. In the pre- and postsurgical studies, OJ predicted postoperative VA very well in patients with moderate cataract and normal fundi and better than all the PVTs. OJ performed less well in patients with comorbid eye disease and dense cataracts, when information from the PVTs would probably have been useful. CFF provided the most accurate predictions of postoperative VA in the small sample of patients with dense cataracts. CONCLUSIONS. CFF was unaffected by cataract, yet sensitive to MD, and provided useful information about the postoperative visual outcome beyond that obtained through history and ocular examination in patients with dense cataracts.

M.Phil. / Previously, not much attention was given to vision and visual skills in the everyday sport setting. The attention that it did get was not from optometry and ophthalmology, these two were late comers on this subject, but more and more athletes and coaches are realizing the importance of vision in their sport performance, although vision training were done inadvertently in the past. Sport performance involves motor and vision aspects. If the motor section does not work efficiently, the vision section will be hampered; in return, if the vision section does not work efficiently, the motor section will also be hampered. For this reason, vision was investigated. In this study an investigation was done on 17-year old (n = 35) and 15-year old (n = 28) rugby players. The aim of this study was to determine whether the visual skills of the 17-year-old boys would be better than that of the 15-year-old boys. Both groups were subjected to a battery of eleven rugby related visual tests. The results obtained, show that in some of the software skills such as eye-hand coordination, eye-body coordination and visual reaction time the 17-year-old group performed statistically better (p<0.05) than the 15-year-old group. The latter group only performed statistically better (p<0.05) in skills classified as hardware skills such as static visual acuity, contrast sensitivity and stereopsis. The results showed a general lack of visual skills. Sport specific visual training programmes will be needed to motor performance training if these athletes are going to develop in elite performers. / Professor Jannie Ferreira

D.Phil. (Optometry) / An important issue in the quantitative analysis of optical systems is, for example, the question of how to calculate an average of a set of eyes. An average that also has an optical character as a whole and is representative or central to the optical characters of the eyes within that set of eyes. In the case of refraction, an average power is readily calculated as the arithmetic average of several dioptric power matrices. The question then is: How does one determine an average that represents the average optical character of a set of eyes, completely to first order? The exponential-mean-log transference has been proposed by Harris as the most promising solution to the question of the average eye. For such an average to be useful, it is necessary that the exponential-mean-log-transference satisfies conditions of existence, uniqueness and symplecticity, The first-order optical nature of a centred optical system (or eye) is completely characterized by the 4x4 ray transference. The augmented ray transference can be represented as a 5x5 matrix and is usually partitioned into 2x2 and 2x 1 submatrices. They are the dilation A, disjugacy B, divergence C, divarication D, transverse translation e and deflection 1t. These are the six fundamental first-orders optical properties of the system. Other optical properties, called derived properties, of the system can be obtained from them. Excluding decentred or tilted elements, everything that can happen to a ray is described by a 4x4 system matrix. The transference, then, defines the four A, B, C and D fundamental optical properties of the system…

The modern school realizes that education is not a mere matter of gaining knowledge; it is a matter of life and growth, with this idea of education in mind, the health of the school child became of great importance. The primary purpose of this investigation is to make an analysis of the visual testing program in the common school districts of Denton County, list the results or outcomes, and make recommendations for future action. A secondary purpose is a review of literature to emphasize the responsibility of the school to discover visual deficiencies, to stress the part that good vision plays in the learning process, and to describe some satisfactory visual teaching devices.

After over a decade of its discovery, the Electroretinogram (ERG) still remains the objective tool that is conventionally used in assessment of retinal function in health and disease. Although there is ongoing research in developing ERG recording techniques, interpretation and clinical applications, there is still a limited understanding on how each photoreceptor class contribute to the ERG waveform and their role and/or susceptibilities in various retinal diseases still remains unclear. Another limitation with currently used conventional testing protocols in a clinical setting is the requirement of an adaptation period which is time consuming. Furthermore, the ERG responses derived in this manner are recorded under different stimulus conditions, thus, making comparison of these signals difficult. To address these issues and develop a new testing method, we employed silent substitution paradigm in obtaining cone- and rod- isolating ERGs using sine- and square- wave temporal profiles. The ERGs achieved in this manner were shown to be photoreceptor-selective. Furthermore, these responses did not only provide the functional index of photoreceptors but their contributions to their successive postreceptoral pathways. We believe that the substitution stimuli used in this thesis could be a valuable tool in functional assessment of individual photoreceptor classes in normal and pathological conditions. Furthermore, we speculate that this method of cone/rod activity isolation could possibly be used in developing faster and efficient photoreceptor-selective testing protocols without the need of adaptation. / Bradford School of Optometry and Vision Sciences scholarship