ABSTRACT
PURPOSE: When observers focus their stereoscopic visual system for a long time (e.g., watching a 3D movie) they may experience visual discomfort or asthenopia. We tested two types of models for predicting visual fatigue in a task in which subjects were instructed to discriminate between 3D characters. One model was based on viewing distance (focal distance, vergence distance) and another in visual direction (oculomotor imbalance). METHOD: A 3D test was designed to assess binocular visual fatigue while looking at 3D stimuli located in different visual directions and viewed from two distances from the screen. The observers were tested under three conditions: (a) normal vision; (b) wearing a lens (-2 diop.); (c) wearing a base-out prism (2â¿) over each eye. Sensitivity and specificity were calculated (as Signal Detection Theory parameters: SDT). RESULTS: An ANOVA and SDT analyses revealed that impaired visual performance were directly related to short distance and larger deviation in visual direction, particularly when the stimuli were located nearer and at more than 24° to the centre of the screen in dextroversion and beyond. CONCLUSION: This results support a mixed model, combining a model based on the visual angle (related to viewing distance) and another based on the oculomotor imbalance (related to visual direction). This mixed model could help to predict the distribution of seats in the cinema room ranging from those that produce greater visual comfort to those that produce more visual discomfort. Also could be a first step to pre-diagnosis of binocular vision disorders.
Subject(s)
Accommodation, Ocular/physiology , Asthenopia/physiopathology , Depth Perception/physiology , Imaging, Three-Dimensional , Photic Stimulation/methods , Vision Tests/methods , Vision, Binocular/physiology , Adult , Asthenopia/diagnosis , Asthenopia/etiology , Eye Movements/physiology , Female , Healthy Volunteers , Humans , Male , Young AdultABSTRACT
En la sociedad actual el trabajo con computadoras se ha convertido en una necesidad, sin embargo, muy pocos médicos han estudiado los efectos nocivos sobre la salud que dicho equipo pudiera ocasionar. Este trabajo esta dirigido a reflejar la relación existente entre el daño ocular y el uso de la computadora en condiciones inadecuadas, así como describir las condiciones ergonómicas a tener en cuenta para prevenir el daño visual durante el trabajo con las computadoras. Se realizó una revisión bibliográfica sobre este tema en Internet y la literatura impresa nacional e internacional. Los daños oculares encontrados están casi todos en el orden de los síntomas y signos astenópicos. Los mismos se reducen notablemente con el trabajo en adecuadas condiciones ergonómicas dadas por variables como: tiempo de exposición, distancia y ángulo de trabajo, iluminación y reflejos, disposición del mobiliario, presencia o no de tóxicos en el ambiente, temperatura y humedad ambiental(AU)
In today´s society, working with computers has become a necessity; however, very few doctors have studied the harmful effects of this device on health. This paper was aimed at reflecting the relationship between eye damage and the use of computer under inadequate conditions, as well as at describing the ergonomic conditions to be taken into account to prevent the visual damage while working with the computers. A literature review on these topics was made on Internet and in national and international hardcopy literature. Almost all the ocular damage found so far is asthenopic symptoms and signs. These problems remarkably decrease when an individual is working under appropriate ergonomic conditions based on variables as length of exposure, distance and working angle, lighting and reflexes, placing of furniture, presence or absence of toxic substances in the environment, temperature and humidity(AU)
Subject(s)
Humans , Male , Female , Asthenopia , Computers , Occupational HealthABSTRACT
En la sociedad actual el trabajo con computadoras se ha convertido en una necesidad, sin embargo, muy pocos médicos han estudiado los efectos nocivos sobre la salud que dicho equipo pudiera ocasionar. Este trabajo esta dirigido a reflejar la relación existente entre el daño ocular y el uso de la computadora en condiciones inadecuadas, así como describir las condiciones ergonómicas a tener en cuenta para prevenir el daño visual durante el trabajo con las computadoras. Se realizó una revisión bibliográfica sobre este tema en Internet y la literatura impresa nacional e internacional. Los daños oculares encontrados están casi todos en el orden de los síntomas y signos astenópicos. Los mismos se reducen notablemente con el trabajo en adecuadas condiciones ergonómicas dadas por variables como: tiempo de exposición, distancia y ángulo de trabajo, iluminación y reflejos, disposición del mobiliario, presencia o no de tóxicos en el ambiente, temperatura y humedad ambiental.
In today´s society, working with computers has become a necessity; however, very few doctors have studied the harmful effects of this device on health. This paper was aimed at reflecting the relationship between eye damage and the use of computer under inadequate conditions, as well as at describing the ergonomic conditions to be taken into account to prevent the visual damage while working with the computers. A literature review on these topics was made on Internet and in national and international hardcopy literature. Almost all the ocular damage found so far is asthenopic symptoms and signs. These problems remarkably decrease when an individual is working under appropriate ergonomic conditions based on variables as length of exposure, distance and working angle, lighting and reflexes, placing of furniture, presence or absence of toxic substances in the environment, temperature and humidity.
