120 research outputs found
Estudio de prácticas de modelación con estudiantes de México y Chile
Este trabajo es parte de una investigación que estudia prácticas de modelación en diversos escenarios con la intención de analizar las herramientas que surgen en este proceso. Se reportan experiencias con estudiantes, de nivel medio superior y superior de México y Chile, respectivamente, que participaron en puestas en escena de un diseño de aprendizaje basado en la modelación lineal. Sus producciones muestran argumentos, herramientas y procedimientos que utilizan al modelar, su análisis presenta invariantes y particularidades que exhiben el rol del estudiante en cada escenario. El trabajo se enmarca en la socioepistemología como perspectiva teórica
Changes in Visual Performance under the Effects of Moderate–High Alcohol Consumption: The Influence of Biological Sex
The purpose of this study was to analyze the changes in visual functions under the effects
of moderate–high breath alcohol concentrations (BrACs), and the influence of biological sex on visual
deterioration, considering different factors. A total of 37 healthy habitual alcohol users were enrolled
in the experiment. The participants underwent a baseline session and a second session after an intake
of 450 mL of red wine, so that all of them reached a BrAC above 0.25 mg/L. Visual performance was
assessed by measuring the contrast sensitivity function, the halo perception, the stereopsis, and finally
the retinal image quality. A Visual Deterioration Score (VDS) was calculated using the deterioration
of these visual variables. All visual functions analyzed were significantly impaired following alcohol
consumption (p < 0.05). The VDS was associated with the BrAC (ρ = −0.476). The VDS was also
significantly higher in females, with the BrAC having a significant effect on the variability of the VDS
in males and females (p 0.05).
Visual functions were significantly impaired under the influence of alcohol, and this deterioration
was greater in females. The deterioration depends on the BrAC reached, being the primary thing
responsible for the differences observed between males and females.Ministry of Economy and Competitiveness (Spain)European Regional Development Fund (ERDF) (FIS2017-85058-R
Visual performance after the deterioration of retinal image quality: induced forward scattering using Bangerter foils and fog filters
We induced and evaluated different levels of retinal-image degradation using Bangerter foils and fog filters. We found increased straylight and an important deterioration in visual performance, assessed by means of visual acuity, contrast threshold, and visual discrimination capacity. Bangerter foils induced forward scattering levels comparable to those observed in mature to severe cataracts, with an important impact of halos and starbursts. Fog filters induced lower levels of intraocular scattering, although luminous veils and circular halos were reported. The visual disturbance index positively correlated with intraocular scattering and straylight. Our results show retinal-image quality has an important influence on night-vision performance.Ministerio de Economía y Competitividad 10.13039/501100003329 (FIS2017-85058-R
Driver distraction by smartphone use (WhatsApp) in different age groups
This paper investigates the effect that texting with WhatsApp, one of the most common applications for instant messaging, exerts on driving performance. Because distracted driving also affects older drivers, who can have seriously compromised vision, we also analysed the associations between visual-function parameters and driving performance. A total of 75 drivers, experienced in sending WhatsApp messages (≥10WhatsApp messages/week), participated in this study and were divided into four age categories. Visual-function tests included contrast sensitivity with and without glare, retinal straylight and objective assessment of optical quality. Simulated driving performance was assessed under a baseline driving condition (without distraction) as well as a texting condition (WhatsApp messages) while driving. The participants used their own mobile phone. Lastly, objective results of driving performance were compared with subjective self-report data from the Driver Behaviour Questionnaire (DBQ). The analysis indicated that functional changes occurring with age, such as a lower contrast sensitivity and greater retinal straylight, were correlated with a higher number of collisions, longer distances driven outside the lane, and greater standard deviation of lateral position (SDLP). The results showed a significant main effect of age for the driving-performance parameters. Also, compared to the baseline, texting WhatsApp messages while driving worsens driving performance for all age groups, most notably among older participants. Thus, the older drivers' SDLP was ~14% higher than that for the baseline average of all the other drivers and rose to 29%
under distraction, reflecting the impact of secondary tasks. The negative effect of the use of the smartphone during driving was also reflected in the number of collisions, with a greater risk of accidents in all the groups of drivers (by 8.3% for young adults, 25.0% for adults, 80.5% for middle-aged adults, and 134.5% for older drivers). Lastly, participants' subjective responses indicated that younger drivers (18–24 years) had a higher risk of deliberately violating safe driving practices (p<0.05). The present study demonstrates that texting WhatsApp messages while driving significantly impairs the ability to drive safely, with older drivers being the group most adversely affected. It would be recommendable to include other nonstandard vision tests, which have shown associations with driving performance, in the examination for driver licensing. This would help raise the awareness of older drivers concerning their visual limitations, permitting them to adopt compensatory measures to improve their driving safety. Nevertheless, it is also necessary to raise awareness among the younger drivers of the risks involved in behaviour behind the wheel
The Relationship between Anxiety, Visual Function, and Symptomatology in University Students
Mental health concerns have emerged at the university level, with the psychological wellbeing
of students being increasingly affected. This cross-sectional study investigated the proportion
of university students having anxiety, and its effects on their visual function and symptomatology. We
included 41 students (26.1 4.8 years), and their visual function was assessed through several tests
to produce a general visual performance index (VPI). The visual symptomatology was studied using
the Conlon Visual Discomfort Survey and the Quality of Vision (QoV) questionnaire. The students
were classified into two groups according to the Generalized Anxiety Disorder Screener (GAD-7)
test (“no anxiety” and “anxiety” groups). The visual function evaluation indicated significantly
worse VPI in the anxiety group (p = 0.047). These students also showed significantly higher scores
in the Conlon survey (p = 0.004) and two subscales of the QoV questionnaire: symptom severity
(p = 0.041) and symptom bothersomeness (p = 0.013). Moreover, the multiple linear regression model
showed a significant association between visual discomfort according to the Conlon questionnaire
and the level of anxiety (r = 0.405; R2 = 0.164; B = 0.405; p = 0.012). It is important to study the
influence of psychological factors on vision, not only for refractive error, but also for binocular and
accommodative disorder
Effects of cannabis on visual function and self-perceived visual quality
Cannabis is one of the most used drugs of abuse in the world. The objective of this study was to
analyze the effects of smoking cannabis on vision and to relate these to those perceived by the user.
Thirty-one cannabis users participated in this study. Visual function assessment was carried out
in a baseline session as well as after smoking cannabis. We evaluated static visual acuity, contrast
sensitivity, stereoacuity, accommodative response, straylight, night-vision disturbances (halos) and
pupil size. The participants were also divided into two groups depending on whether they perceived
their vision to have worsened after smoking cannabis. A logistic regression analysis was employed to
identify which visual test could best predict self-perceived visual effects. The study found that smoking
cannabis has significant adverse effects on all the visual parameters analyzed (p < 0.05). Self-perceived
visual quality results revealed that about two thirds of the sample think that smoking cannabis impairs
their vision. Contrast sensitivity, specifically for the spatial frequency 18 cpd, was identified as the
only visual parameter significantly associated with self-perceived visual quality (Odds Ratio: 1.135;
p = 0.040). Smoking cannabis is associated with negative effects on visual function. Self-perceived
visual quality after smoking cannabis could be related to impaired contrast sensitivity
Stereopsis simulating small aperture corneal inlay and monovision conditions
Purpose: To analyze stereoscopic vision under a broad range of experimental conditions simulating small-aperture corneal inlay and monovision conditions.
Methods: A total of 10 patients participated in the study. The anisocoria generated by corneal inlays was simulated by using a small-aperture contact lens fitted on the non-dominant eye. Visual acuity, contrast sensitivity function, visual discrimination capacity (halo perception), and stereoacuity tests were performed under natural conditions or when the non-dominant eye wore the small-aperture contact lens under two conditions: induced anisocoria and induced anisocoria combined with monovision (using two add-powers: +0.75 and +1.25 diopters [D]). Stereoscopic vision and binocular summation were analyzed under those experimental conditions and for far, intermediate, and near vision.
Results: The results showed a deterioration in stereoacuity with respect to natural conditions, being significant mainly for near and intermediate distances. Results with other visual functions showed a deterioration of the binocular summation and therefore of visual performance, although not in a generalized way for all distances. Binocular visual acuity under the conditions that used the small-aperture contact lens was comparable to that of the natural eye.
Conclusions: The deterioration of stereopsis and other binocular functions found in this study may be acceptable for patients who had this surgical technique because it is similar to the deterioration found in other surgical procedures of emmetropization.Ministerio de Economía y Competitividad y Fondo Regional Europeo para el Desarrollo (Grant FIS2013-42204-R)Ministerio de Educación, Cultura y Deporte (FPU15/05571
Contrast sensitivity and retinal straylight after alcohol consumption: effects on driving performance
El objetivo de este estudio es investigar los efectos del consumo de alcohol en la función visual y en el rendimiento en la conducción, así como la relación entre ambas funciones. Un total de 40 participantes sanos participaron en las tres sesiones experimentales llevadas a cabo en el estudio: una sesión de control (sin consumo de alcohol), y otras dos sesiones más tras consumir alcohol (una tras consumir 300ml de vino tino y otra tras consumo de 450ml del mismo vino). Se midió el contenido de alcohol en aire espirado (BrAC, en mg/l) usando un etilómetro. Para caracterizar la función visual se midieron la sensibilidad al contraste así como el velo luminoso o luz difundida hacia la retina (retinal straylight), debido este último a la difusión luminosa intraocular. El rendimiento en la conducción fue evaluado en tres escenarios (autovía, carretera de montaña y entorno urbano) usando un simulador de conducción. Los resultados mostraron un deterioro tras consumo de alcohol en la sensibilidad al contraste y en el velo luminoso retiniano (aumento del retinal straylight), además de una deteriorada habilidad para conducir, especialmente para la ingesta mayor de alcohol. También se observó que, bajo los efectos del consumo de alcohol, el rendimiento deteriorado en la conducción dependía de la sensibilidad al contraste y del velo luminoso retiniano, indicando que estas variables visuales pueden parcialmente predecir el rendimiento en la conducción en estas condiciones.In this study, we aimed to investigate the effects of alcohol intake on visual function and driving performance, as well as on the relationship between these. A total of 40 healthy participants took part in three experimental sessions: one baseline session and two further sessions after consuming two different quantities of alcohol (300 ml and 450 ml of red wine). The breath alcohol content (BrAC) was measured using a breath analyzer. The contrast sensitivity and retinal straylight due to the forward intraocular scattering were measured to characterize visual function, and driving performance was assessed in three different scenarios using a driving simulator. The results showed a deterioration in contrast sensitivity and retinal straylight after drinking alcohol, in addition to an impaired ability to drive, especially for the highest alcohol intake. We also observed that the deteriorated driving performance was a function of the contrast sensitivity and retinal straylight under the effects of alcohol, indicating that these visual variables can partially predict driving performance in these conditions.Ministerio de Economía y Competitividad; European Regional Development Fund (ERDF) (referencia FIS2017-85058-R
Intraocular scattering as a predictor of driving performance in older adults with cataracts
Cataracts can limit a person's ability to perform vision-dependent tasks safely, affecting the quality of life of older people. This study examines the relationship between visual function and driving, by studying which visual parameters might be important for predicting driving performance in older drivers with and without cataracts, ascertaining whether the objective measurement of intraocular scattering should be considered in assessment procedures for older drivers. This cross-sectional study involved a total of 20 older drivers (10 patients with bilateral cataracts and 10 control subjects). All participants were examined for visual acuity, contrast sensitivity, visual discrimination capacity, and intraocular scattering. Driving performance was also tested using a driving simulator. To study the relationship between visual parameters and driving performance, a correlation analysis and regression model were used. Drivers with cataracts showed a significantly impaired (p<0.05) visual function, with an Objective Scattering Index (OSI) 3.5 times greater than the control group. Driving performance was also significantly worse (p<0.05) in drivers with cataracts, reflected by a notable deterioration in lane keeping. The correlation analysis showed significant associations between driving performance and all the visual parameters studied. Finally, the regression model revealed that the OSI was the best predictor of driving performance, accounting for 51.3% of its variance. Visual function and driving performance are markedly deteriorated when cataracts are present. Our results demonstrate that the objective scattering index (OSI) has a high predictive power when it comes to simulated driving performance in older drivers, both with and without cataracts, suggesting that scatter measurements could be important in helping better understand visual limitations in older drivers
Impact of Age-Related Vision Changes on Driving
Aging leads to impaired visual function, which can affect driving—a very visually
demanding task—and has a direct impact on an individual’s quality of life if their license is
withdrawn. This study examined the associations between age-related vision changes and simulated
driving performance. To this end, we attempted to determine the most significant visual parameters
in terms of evaluating elderly drivers’ eyesight. Twenty-one younger drivers (aged 25–40) were
compared to 21 older drivers (aged 56–71). Study participants were assessed for visual acuity,
contrast sensitivity, halos, and intraocular straylight, which causes veiling luminance on the retina and
degrades vision. Driving performance was evaluated using a driving simulator. The relationships
between simulated driving performance and the visual parameters tested were examined with
correlation analyses and linear regression models. Older drivers presented impairment in most visual
parameters (p < 0.05), with straylight being the most significantly affected (we also measured the
associated effect size). Older drivers performed significantly worse (p < 0.05) in the simulator test,
with a markedly lower performance in lane stability. The results of the multiple linear regression
model evidenced that intraocular straylight is the best visual parameter for predicting simulated
driving performance (R2 = 0.513). Older drivers have shown significantly poorer results in several
aspects of visual function, as well as difficulties in driving simulator performance. Our results suggest
that the non-standardized straylight evaluation could be significant in driver assessments, especially
at the onset of age-related vision changes.ministry of economy and competitiveness (spain)European Union (EU)
FIS2017-85058-Rministry of science, innovation and universities (spain)
FPU15/0557
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