scholarly journals Improvement of Visual Acuity in Partially and Fully Sighted Subjects as a Function of Practice, Feedback, and Instructional Techniques

1978 ◽  
Vol 46 (3) ◽  
pp. 815-822 ◽  
Author(s):  
Olga Overbury ◽  
Michael Bross
Keyword(s):  
Visual Acuity ◽  
Theoretical Model ◽  
Depth Perception ◽  
Optic Atrophy ◽  
Unexpected Finding ◽  
Testing Session ◽  
Vernier Acuity ◽  
The Third ◽  
Visual Improvement ◽  
Binocular Depth

Three experiments were conducted to examine improvement of partially (20/200 or 6/60) and normally (20/20 or 6/6) sighted adults. Measures of resolution and vernier acuity were examined in the first two experiments to determine whether practice, feedback, and instructions would have differential effects on the degree of visual improvement achieved in a 20-min. testing session. The results indicated extensive visual work to be the important factor in the improvement of impaired vision. The third experiment compared monocular and binocular depth perception of individuals with unilateral optic atrophy. The results yielded an unexpected finding where binocular depth perception was, in most cases, inferior to that of the strong eye alone. The first two experiments demonstrated the possibility of improving impaired visual functions and the third experiment suggests important implications for a theoretical model of depth perception with limited vision.

Binocular depth perception following early experience with interocular torsional disparity

1992 ◽  
Vol 9 (3-4) ◽  
pp. 303-312 ◽  
Author(s):  
Paul G. Shinkman ◽  
Brian Timney ◽  
Michael R. Isley
Keyword(s):  
Visual Acuity ◽  
Visual Cortex ◽  
Depth Perception ◽  
Visual Experience ◽  
Early Experience ◽  
Field Orientation ◽  
Visual Exposure ◽  
The Mean ◽  
The Relationship ◽  
Binocular Depth

AbstractThe relationship between the behavioral and physiological consequences of rearing with optically induced cyclotropia was assessed. Beginning at the age of 4 weeks, kittens wore goggles that rotated the visual field in opposite directions in each eye for several hours each day over a period of several weeks. The amounts of interocular rotation were 0 deg (control), 16 deg, and 32 deg. Subsequently, they were tested to determine their monocular and binocular depth thresholds and, in some cases, visual acuity. In several kittens recordings were also made from the visual cortex. Binocular performance of all kittens in the 0-deg condition and three out of six kittens in the 16-deg condition was comparable to, although slightly lower than, that of normally reared kittens. In contrast, none of the 32-deg kittens showed any evidence of the binocular superiority that would suggest the presence of stereopsis. Extracellular unit recordings from the visual cortex confirmed our earlier results with goggle-reared kittens. In 16-deg kittens, the distribution of the cells' preferred interocular disparities (IOD) in receptive-field orientation showed a compensating shift so that the mean matched the experienced rotational disparity. In the 32-deg kittens, binocularity was greatly disrupted and there was no compensatory shift in the IOD distribution. Two 32-deg kittens were afforded 3 years of subsequent normal visual experience. Both the behavioral and the physiological findings were unaffected by normal visual exposure in adulthood. Control measurements of acuity indicated that any deficits in depth perception were not due to reduced spatial-resolution abilities. The data indicate that the kitten visual system is able to maintain functional binocularity sufficient to subserve a moderate level of stereoacuity with interocular rotations of up to at least 16 deg.

scholarly journals A relação entre ciência e tecnologia a partir de três modelos teóricos distintos

DoisPontos ◽  
2015 ◽  
Vol 12 (1) ◽  
Author(s):  
Gilmar Evandro Szczepanik
Keyword(s):  
Theoretical Model ◽  
Science And Technology ◽  
Theoretical Models ◽  
The Third

resumo: Este artigo tem por objetivo explorar as possíveis relações estabelecidas entre ciência e a tecnologia a partir de três modelos teóricos distintos. O primeiro modelo teórico é chamado de hierárquico e pressupõe uma relação de subordinação entre ciência e a tecnologia. O segundo modelo é denominado de não hierárquico e sustenta que ciência e a tecnologia se encontram fundidas de tal modo que não faz mais sentido tentar entendê-las separadamente. Por fim, o terceiro modelo teórico designado de emancipatório explora alguns elementos que permitem compreender a ciência e a tecnologia ainda como atividades distintas, embora possam trabalhar conjuntamente algumas vezes.Abstract:  This paper aims to  understand the possible  relations between science and technology from three different theoretical models. The first theoretical model is called hierarchical and implies a subordinate relationship between science and technology. The second model  is  called non-hierarchical  and argues  that  science  and technology are fused so that it makes more sense to try to understand them separately. Finally, the third theoretical model is called emancipatory  and explores some elements that allow us to understand science and technology as separate activities, although they may sometimes work together. 

scholarly journals Association between individual retinal layer thickness and visual acuity in patients with epiretinal membrane: a pilot study

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9481
Author(s):  
Jing Zou ◽  
Wei Tan ◽  
Wenlong Huang ◽  
Kangcheng Liu ◽  
Fangling Li ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Layer Thickness ◽  
Epiretinal Membrane ◽  
Linear Regression Analysis ◽  
Plexiform Layer ◽  
Surgical Patients ◽  
Retinal Layer ◽  
Inner Plexiform Layer ◽  
Post Surgery ◽  
Visual Improvement

Purpose We investigated the correlation between visual acuity (VA) and individual retinal layer thickness in the foveal, parafoveal, and perifoveal regions of patients with an idiopathic epiretinal membrane (ERM). Methods One hundred and five subjects presenting with unilateral idiopathic ERM were included in this study. We segmented each patient’s optical coherence tomography (OCT) image into seven layers and calculated the mean layer thickness in the foveal, parafoveal, and perifoveal regions using the Iowa Reference Algorithm. In 105 patients with ERM, we detected correlations between their macular regions’ individual retinal layer thickness and their best corrected VA. Thirty-one of the 105 patients with ERM underwent vitrectomy and completed six months of follow-up. We then compared the 31 surgical patients’ preoperative and postoperative individual retinal layer thickness in each macular region. Additionally, the association between preoperative individual retinal layer thickness in each macular region and VA six months post-surgery in patients with ≥ two Snellen lines of visual improvement was determined. Results Multiple linear regression analysis showed that the inner nuclear layer (INL) thickness in the foveal, parafoveal, and perifoveal region were all associated with VA in the 105 patients (R2 = 0.344, P < 0.001; R2 = 0.427, P < 0.001; and R2 = 0.340, P < 0.001, respectively). Thirty-one surgical patients 6 months post-surgery showed significantly decreased thicknesses (P ≤ 0.012) of the foveal INL, inner plexiform layer (IPL), and outer nuclear layer (ONL); the parafoveal retina nerve fiber layer (RNFL), IPL, INL, and ONL; and the perifoveal RNFL, IPL, INL, ganglion cell layer (GCL), outer plexiform layer (OPL), and photoreceptor layer (PRL). We found a weak correlation between postoperative VA and preoperative foveal and perifoveal RNFL thickness (r = 0.404 and r = 0.359, respectively), and a moderate correlation between postoperative VA and preoperative foveal and parafoveal INL thickness (r = 0.529 and r = 0.583, respectively) in the 31 surgical patients (P ≤ 0.047). The preoperative INL thickness in the foveal, parafoveal, and perifoveal regions showed a moderate to strong correlation (r = 0.507, 0.644, and 0.548, respectively), with postoperative VA in patients with ≥ 2 lines of visual improvement (P ≤ 0.038). Conclusion We detected a correlation between retinal damage and VA in the parafoveal, perifoveal, and foveal regions. Our results suggest that INL thickness in all macular regions may be a prognostic factor for postoperative VA in ERM patients.

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