Šiame darbe analizuojama šviesos įtaka regos procesui. Išnagrinėta mokslinė literatūra žmogaus regos, ryškumo, kontrasto ir spalvų suvokimo bei regos aštrumo klausimais. Išanalizuoti žmogaus regos proceso ypatumai, regos fiziologija. Pristatomi pagrindiniai fotometriniai dydžiai bei jų sąsaja su regos sistema. Atliktas tyrimas, kurio metu nustatoma regos aštrumo priklausomybė nuo paviršiaus apšvietos. Tyrime dalyvavo 50 žmonių. Tiriamieji suskirstyti į dvi: 40-50 ir 51-60 metų amžiaus grupes. Tyrime nustatyta, tiriamųjų regos aštrumo priklausomybė nuo įvairių apšvietų, apskaičiuoti vidutiniai tyrimo duomenų rezultatai, pateikta, tyrimo eigoje išryškėjusi adaptacijos tamsai įtaka. Šie tyrimo duomenys pavaizduoti grafiškai. Analizuojant teorinę medžiagą pastebėta, kad Lietuvoje, tai mažai tyrinėta sritis. Gauti tyrimo rezultatai rodo, kad padarius didesnius, daug daugiau tiriamųjų, kriterijų, apimančius tyrimus, būtų galima gauti įdomių rezultatų. / The subject of the work is the investigation of the visual acuity dependence on surface illumination. This final work analyzes the influence of light to visual process. Scientific literature was studied to look into the issues of human’s eyesight, brightness, contrast and color perception and visual acuity. The features of the human visual process and physiology of human’s eyesight have been examined as well. The work introduces the main photometric values and their relation to the visual system. The investigation has been carried out to determine the dependence of visual acuity on the surface illumination with 50 people participating in it. The people were divided into two groups according to their age: 40-50 and 51-50. The average data of the results have been estimated and various deviations from the mean shown up during the investigation are graphically presented in the work. While studying the theoretical material it was noticed that this field is still a byway in Lithuania. The findings suggest that if deeper and more criteria spanning researches were carried out, more revealing results could be expected.

Myopia is a major cause of vision loss throughout the world. High myopia is associated with severe eye diseases like maculopathy, retinal detachment and glaucoma. The prevalence of myopia is increasing, and varies by country and by ethnic group. In some Asian populations the prevalence is 70%-80%.  This thesis includes five experiments. In experiment I we investigated the effects of added positive and negative spherical aberration on accommodative response accuracy. We found that the accommodative response can be altered by modulating the spherical aberration of the eye with soft contact lenses. There was an improvement in the accommodative response slopes and a decrease in the lag of accommodation with the negative spherical aberration lenses compared to positive spherical aberration lenses.  In experiment II we investigated whether the negative spherical aberration in contact lenses could be tolerated visually in terms of wearability and comfort. We found that all the subjects were satisfied with the contact lens comfort, distance and near vision and the stability of the vision with the lenses. The accommodative response was stable through out the treatment period. In experiment III we investigated the efficacy of a novel dual treatment for the improvement of accommodative accuracy and dynamics in myopes. The spherical aberration of the eye was effectively altered to negative in the treatment group as predicted. In the control group as expected there was no significant change in the spherical aberration of the eye with and without contact lenses. The treatment lenses decreased the lag of accommodation and increased the accommodative response slope at 3 months. In the experiment IV we investigated the effect of the treatment lenses used in the previous experiment on high and low contrast visual acuities after a one year treatment period. The results showed a significant improvement in both high and low contrast visual acuities after the one year period in the treatment group compared to the control group, even though it was not clinically significant. In experiment V we investigated the intrasession repeatability of peripheral aberrations using COAS-HD VR aberrometer and also reported the distribution of higher order aberrations in a group of young emmetropes. There was no significant difference in the variance of total higher-order RMS between on- and off-axis measurements. There was a significant change in the horizontal coma, spherical aberration and higher-order RMS with off-axis angle along the horizontal visual field. We demonstrated that fast, repeatable and valid peripheral aberration measurements can be obtained with this instrument. This thesis contributes new results in this field of myopia, aberration and accommodation.

Background/Aims: In an investigation of the functional impact of amblyopia on children, the fine motor skills, perceived self-esteem and eye movements of amblyopic children were compared with that of age-matched controls. The influence of amblyogenic condition or treatment factors that might predict any decrement in outcome measures was investigated. The relationship between indirect measures of eye movements that are used clinically and eye movement characteristics recorded during reading was examined and the relevance of proficiency in fine motor skills to performance on standardised educational tests was explored in a sub-group of the control children. Methods: Children with amblyopia (n=82; age 8.2 ± 1.3 years) from differing causes (infantile esotropia n=17, acquired strabismus n=28, anisometropia n=15, mixed n=13 and deprivation n=9), and a control group of children (n=106; age 9.5 ± 1.2 years) participated in this study. Measures of visual function included monocular logMAR visual acuity (VA) and stereopsis assessed with the Randot Preschool Stereoacuity test, while fine motor skills were measured using the Visual-Motor Control (VMC) and Upper Limb Speed and Dexterity (ULSD) subtests of the Brunicks-Oseretsky Test of Motor Proficiency. Perceived self esteem was assessed for those children from grade 3 school level with the Harter Self Perception Profile for Children and for those in younger grades (preschool to grade 2) with the Pictorial Scale of Perceived Competence and Acceptance for Young Children. A clinical measure of eye movements was made with the Developmental Eye Movement (DEM) test for those children aged eight years and above. For appropriate case-control comparison of data, the results from amblyopic children were compared with age-matched sub-samples drawn from the group of children with normal vision who completed the tests. Eye movements during reading for comprehension were recorded by the Visagraph infra-red recording system and results of standardised tests of educational performance were also obtained for a sub-set of the control group. Results Amblyopic children (n=82; age 8.2 ± 1.7 years) performed significantly poorer than age-matched control children (n=37; age 8.3 ± 1.3 years) on 9 of 16 fine motor skills sub-items and for the overall age-standardised scores for both VMC and ULSD items (p<0.05); differences were most evident on timed manual dexterity tasks. The underlying aetiology of amblyopia and level of stereoacuity significantly affected fine motor skill performance on both items. However, when examined in a multiple regression model that took into account the inter-correlation between visual characteristics, poorer fine motor skills performance was only associated with strabismus (F1,75 = 5.428; p =0. 022), and not with the level of stereoacuity, refractive error or visual acuity in either eye. Amblyopic children from grade 3 school level and above (n=47; age 9.2 ± 1.3 years), particularly those with acquired strabismus, had significantly lower social acceptance scores than age-matched control children (n=52; age 9.4 ± 0.5 years) (F(5,93) = 3.14; p = 0.012). However, the scores of the amblyopic children were not significantly different to controls for other areas related to self-esteem, including scholastic competence, physical appearance, athletic competence, behavioural conduct and global self worth. A lower social acceptance score was independently associated with a history of treatment with patching but not with a history of strabismus or wearing glasses. Amblyopic children from pre-school to grade 2 school level (n=29; age = 6.6 ± 0.6 years) had similar self-perception scores to their age-matched peers (n=20; age = 6.4 ± 0.5 years). There were no significant differences between the amblyopic (n=39; age 9.1 ± 0.9 years) and age-matched control (n = 42; age = 9.3 ± 0.38 years) groups for any of the DEM outcome measures (Vertical Time, Horizontal Time, Number of Errors and Ratio (Horizontal time/Vertical time)). Performance on the DEM did not significantly relate to measures of VA in either eye, level of binocular function, history of strabismus or refractive error. Developmental Eye Movement test outcome measures Horizontal Time and Vertical Time were significantly correlated with reading rates measured by the Visagraph for both reading for comprehension and naming numbers (r>0.5). Some moderate correlations were also seen between the DEM Ratio and word reading rates as recorded by Visagraph (r=0.37). In children with normal vision, academic scores in mathematics, spelling and reading were associated with measures of fine motor skills. Strongest effect sizes were seen with the timed manual dexterity domain, Upper Limb Speed and Dexterity. Conclusions Amblyopia may have a negative impact on a child’s fine motor skills and an older child’s sense of acceptance by their peers may be influenced by treatment that includes eye patching. Clinical measures of eye movements were not affected in amblyopic children. A number of the outcome measures of the DEM are associated with objective recordings of reading rates, supporting its clinical use for identification of children with slower reading rates. In children with normal vision, proficiency on clinical measures of fine motor skill are associated with outcomes on standardised measures of educational performance. Scores on timed manual dexterity tasks had the strongest association with educational performance. Collectively, the results of this study indicate that, in addition to the reduction in visual acuity and binocular function that define the condition, amblyopes have functional impairment in childhood development skills that underlie proficiency in everyday activities. The study provides support for strategies aimed at early identification and remediation of amblyopia and the co-morbidities that arise from abnormal visual neurodevelopment.

Diss. (sammanfattning) Stockholm : Karol. inst., 2002. / CD-ROM i ficka. Härtill 5 uppsatser.

Diss. (sammanfattning) Linköping : Univ., 2004. / Härtill 4 uppsatser.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 52-55). Also available via the Internet.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1976. / Vita. Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 200-214.).

Red interior lighting used to preserve dark-adaptation needs to be replaced in military applications by blue/green lighting which is not detectable by 3rd-generation image intensifiers. This study investigated the influence of blue/green as compared to red and white light of equal photopic intensity on subsequent visual acuity , contrast sensitivity and dark-adaptation. Male subjects (n = 90) were assigned to one of 15 treatment conditions (n = 6) as determined by the colour (blue/green, red or white) and intensity (0.1; 0.4; 1.6; 6.4 and 25.6 cd/m²) of the pre-adaptation stimuli. A modified Goldmann/Weekers adaptometer was used to present the preadaptation stimuli, test stimuli and record visual (luminance) thresholds of each subject. Blue/green lighting had the same affect on visual (photopic) acuity and contrast sensitivity as white and red lighting. Blue/green affected visual (absolute) threshold at the start and during the process of dark-adaptation in the same manner as white but not the same as red lighting. White and red lighting did not differ significantly (p < 0.01) at low intensities (mesopic range) but did at the higher intensities (photopic range). After exposure to blue/green and white light, it will take longer to reach the same level of dark-adaptation than after exposure to red. These time differences increase with" increased intensities. The brightness ratio between red and white lights to produce the same dark-adaptation increases with an increase in intensity. At the upper mesopic region the differences between the effects of white and red lighting on subsequent dark-adaptation become irregular due to the inability to accurately equate non-monochromatic lights in the mesopic range.

O objetivo deste trabalho foi medir o desenvolvimento da acuidade visual (AV) de resolução de grades de filhotes de cães da raça Terrier Brasileiro utilizando-se o método do potencial visual evocado de varredura (PVEV). Foram mensuradas as AVs de resolução de grades de 18 cães da raça Terrier Brasileiro, 14 filhotes (8 machos e 6 fêmeas), de duas ninhadas diferentes e 4 adultos (2 machos e 2 fêmeas, incluindo-se a matriz). Os PVEVs (NuDiva) foram registrados a partir de dois eletrodos ativos posicionados no escalpo em O1 e O2, um eletrodo referência posicionado em OZ e um eletrodo terra em CZ. O estímulo consistiu de padrões reversos de grades de ondas quadradas a uma freqüência de 6 Hz, variando de 0,2 a 12 ciclos por grau (cpg). A luminância média do monitor foi de 159.3 cd/m2. As AVs foram medidas semanalmente a partir da 4ª semana de vida até a 13ª semana. A distância de teste foi de 50 cm e o animal permaneceu no colo de seu acompanhante, com a cabeça suavemente contida para manter os olhos voltados ao estímulo do monitor de vídeo (Dotronix D788). O teste foi realizado em sala escura sem o uso de midriáticos, sedativos ou anestésicos. A mediana da AV dos filhotes variou de 2,28 cpg (Q2= 2,12; Q3= 2,36) (equivalente a 20/265 na escala de Snellen) na 4ª semana para 9,18 cpg (Q2= 8,64; Q3= 9,31) (20/65) na 13ª semana. A mediana de AV dos cães adultos foi de 8,82 cpg (Q2= 8,71; Q3= 8,94) (20/70). Este valor foi atingido pelos filhotes ao redor da 10ª semana. A AV aumentou rapidamente até, aproximadamente, a 7ª semana. Um crescimento mais moderado foi observado até a semana 9. A taxa de crescimento declinou gradualmente a partir da 10ª semana. A partir daí os valores de AV praticamente estabilizam ao redor de 20/65 (&chi;2 = 120,61; p < 0.001). Houve uma diferença estatisticamente significante das AVs a cada quatro semanas (Dunn\'s Method; p< 0,05). Houve uma alta correlação positiva entre a AV e o peso dos animais (R= 0,83; p< 0,001; Spearman Rank Order Correlation). O PVE de varredura é método não invasivo que permite mensurar a AV de forma precisa, sem requerer excessiva cooperação e atenção, na população alvo. O método tem aplicação clínica e investigativa, não sendo necessário o uso de cicloplégicos ou de contenção química. Os filhotes atingiram os valores de acuidade semelhantes aos de adultos na 10ª semana de vida. A AV dos adultos examinados (20/70) está de acordo com estimativas encontradas em outros estudos. A acuidade visual de cães da raça Terrier Brasileiro está entre 8,60 cpg (20/70) e 9,57 cpg (20/60). / Our aim in this study was to measure the development of grating visual acuity (VA) in Brazilian Terrier puppies by sweep visual evoked potentials (sVEP). Grating VAs of 18 Brazilian Terrier dogs, 14 puppies (8 male, 6 female), from two different litters and 4 adults (2 male, 2 female), including the matrix, were measured. Sweep-VEPs (NuDiva) were recorded from two active electrodes placed on the scalp at O1 and O2, a reference electrode at Oz and a ground electrode at Cz. The stimuli were pattern reversal square wave gratings at a rate of 6 Hz, ranging from 0.2 to 12 cycles per degree (cpd). The mean monitor luminance was 159.3 cd/m2. The VAs were measured weekly from the 4th to the 13th week. Viewing distance was 50cm and the pup was positioned on the lap of the investigator with the head gently supported to maintain the eyes in front of the video monitor (Dotronix D788). The test was performed in a darkened room without mydriatic, sedative or anesthetic drugs. The median VA ranged from 2.28 cpd (Q2= 2.12; Q3= 2.36) (equivalent to 20/265 Snellen VA) at the 4th week to 9.18 cpd (Q2= 8.64; Q3= 9.31) (20/65) at the 13th week. The median of adult VA was 8.82 cpd (Q2= 8.71; Q3= 8.94) (20/70). This value was reached by the puppies around the 10th week. VA increase was steeper up to the 7th week than afterwards. The rate of increase gradually declined up to the 10th week (&chi;2= 120.61; p< 0.001). The VAs were statistically different witch four week (Dunn\'s Method; p< 0.05). There was a high positive correlation between the VA and body weight (R= 0.83; p< 0.001; Spearman Rank Order Correlation). The Sweep-VEP method offers a rapid and reliable procedure for the quantification of grating VA in puppies and adults dogs, without the need for sedation. Pup VA reached adult values at the 10th week of life. The mean of adult VA measured (20/70) is in accordance with estimates of VA of dogs in other studies. The range of VA of Brazilian Terrier dogs were 8.60 cpd (20/70) to 9.57 cpd (20/60).

Orientador: Fernanda Aparecida Cintra / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação / Made available in DSpace on 2018-08-08T04:07:37Z (GMT). No. of bitstreams: 1 Borges_SheiladeMelo_M.pdf: 637075 bytes, checksum: da2b46c5af56252ff050def17269c19e (MD5) Previous issue date: 2006 / Resumo: A prevalência da deficiência visual na população idosa é alta. A acuidade visual diminuída tem repercussões importantes na função visual e na capacidade funcional dos idosos. Objetivo - O objetivo do trabalho foi a avaliar a relação entre função visual e capacidade funcional em idosos em seguimento ambulatorial. Método - Foram entrevistados, por meio de instrumento próprio, 64 idosos em seguimento ambulatorial num hospital universitário. Os sujeitos foram divididos em dois grupos, conforme os valores obtidos na medida da AV: o grupo I composto pelos idosos com visão normal ou próxima do normal, e o grupo II formado por aqueles com baixa visão. Os dados foram submetidos à análise univariada, buscando-se as tendências da distribuição das diversas variáveis e os valores de posição e de dispersão de cada variável. Foram realizadas correlações bivariadas entre as variáveis, a fim de identificar as seguintes relações: 1. Entre os grupos (I e II) e os indicadores da condição visual (questões extraídas do instrumento NEI VFQ-25); 2. Entre os grupos (I e II) e a capacidade funcional (Medida da Independência Funcional ¿ MIF; Atividades Instrumentais de Vida Diária - AIVDs; Atividades Expandidas de Vida Diária ¿ AEVDs); 3. Entre indicadores da condição visual e a capacidade funcional. Na análise de covariância multivariada buscou-se verificar a influência das variáveis da função visual sobre as variáveis da capacidade funcional nos idosos. Resultados - Foram observadas diferenças significativas entre os idosos com visão normal ou próxima do normal (grupo I) e aqueles com baixa visão (grupo II), com respeito às variáveis: escolaridade (menor escolaridade no grupo II), indicadores da condição visual (menor auto percepção da visão, maior frustração, insegurança, limitação e dependência no grupo II), e AIVDs (menor escore ou maior dependência no grupo II). Observou-se, ainda, influência entre as variáveis da função visual (AV com os indicadores da condição visual), e entre AV com as AIVDs, sendo esta a única relação significativamente observada entre AV e os instrumentos de capacidade funcional utilizados nesse estudo. Conclusão ¿ houve influência da função visual na capacidade funcional nos idosos pesquisados / Abstact: The prevalence of visual deficiency in elderly people is high. The visual acuity reduced (VA) has important repercussions in the visual function and the functional capacity of the elderly. Objective - the objective is to evaluate the relation between the visual function and the functional capacity of the elderly in clinical segment. Method ¿ through own instruments, sixty-four elderly men and women were interviewed in clinical segment at an academic hospital. They were then divided into two groups in accordance to the values that were obtained through the measure of the VA: the first group consisted of elderly people with normal vision or close to the normal, and the second group was formed of those with low vision. The data were sent to the univariate analysis, looking for the tendencies of distribution of the diverse variables and the values of the position and dispersion of each variable. Bivariate correlations were made between the variables in order to identify the following relations: among the groups (I and II) and the indicators of visual condition (questions extracted from the NEI VFQ-25 instrument); among the groups (I and II) and the functional capacity (Functional Independence Measure ¿ FIM; Instrumental Activities of the Daily Life - IADL; Expanded Activities of Daily Life¿ EADL); among the indicators of the visual condition and the functional capacity. In the co-variance multivaried analysis to verify the influence of the variables of the visual function above the functional capacity of the elderly. Results ¿ significant differences between the elderly with normal vision or close to the normal (group I) and those with low vision (group II) were found: 1.educational level (lower in the second group); 2.indicators of the visual condition (lower autoperception of the vision, higher frustration, insecurity, limitation and dependence in the second group); 3.and IADL (lower score or higher dependence in the second group) It was also noticed the influence among the variables of the visual function (VA with the indicators of the visual condition), and between VA with the IADL, being this the only relation significantly observed between VA and the instruments of functional capacity utilized in this study. Conclusion ¿ the visual function has influence on the functional capacity of the elderly examined. / Mestrado / Mestre em Gerontologia