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Vision
Published in Alfred T. Lee, Vehicle Simulation, 2017
An additional measure of visual acuity applicable to the case of binocular vision is stereo acuity. Human vision consists of two eyes with an interpupillary distance (IPD) averaging about 6.3 cm in adults. Consequently, each eye will be viewing a slightly different image, that is, there will be binocular disparity. The binocular disparity between the images is resolved or fused into a single image at high levels within the cortex for those with normal vision. However, a study of college-age adults found that about 2.7% of those tested were effectively stereo blind and no fusion takes place as a result (Richards, 1970). These individuals will not be able to experience the depth/distance effects of stereoscopic displays. Sustained viewing of these displays may also result in discomfort for these individuals.
Effect of unifocal versus multifocal lenses on cervical spine posture in patients with presbyopia
Published in International Journal of Occupational Safety and Ergonomics, 2019
Rami L. Abbas, Mohamad T. Houri, Mohammad M. Rayyan, Hamada Ahmad Hamada, Ibtissam M. Saab
A repeated-measure design was used to compare the effect of unifocal lenses versus multifocal lenses on cervical posture in patients with symptoms of presbyopia. A digital pupillometer was used to measure the interpupillary distance (IPD) in order to adjust the trial spectacle accordingly, and a vision test was done to determine suitable corrective lenses for each subject. A measuring tape was used to adjust both the table and chair according to specific criteria. The chair seat, which had a lumbar pillow on it, was adjusted in such a way to allow the hips and knees to adopt 90° of flexion, while the feet were resting on the floor. The height of the table was set at 76 cm, which is similar to the standard desk used in the office [11]. The desk had paper placed on top, with letters in the Arial font and a font size of 14 [12]. The paper was 40 cm away from the candidate [13], with 50° inclination with respect to the surface of the desk [14]. To perform the tests, every subject wore a trial frame glass for mounting the related occluder and suitable trial lens for near vision.
Spatialized Vibrotactile Feedback Improves Goal-Directed Movements in Cluttered Virtual Environments
Published in International Journal of Human–Computer Interaction, 2018
Céphise Louison, Fabien Ferlay, Daniel R. Mestre
Subjects were naïve as concerns the purpose of the experiment. All subjects reported normal vision and sense of touch and were free from any locomotor or postural disorder. Their stereoscopic acuity was tested using the Randot® Graded Circles test (Stereo Optical Company Inc, Chicago, IL, USA). Their inter-pupillary distance (IPD) was measured using the Oculus configuration utility software. IPD ranged from 60.6 to 67.9mm (mean = 64.1; SD = 2.2), and was used to adjust stereoscopic rendering to each individual. The subjects were not selected regarding their stature. Their standing height ranged from 163 to 190 cm (mean = 177.6; SD = 7.1).
Impact of parallax and interpupillary distance on size judgment performances of virtual objects in stereoscopic displays
Published in Ergonomics, 2019
Bereket Haile Woldegiorgis, Chiuhsiang Joe Lin, Wei-Zhe Liang
Interpupillary distance (IPD), sometimes called interocular distance (IOD), refers to the distance between the left and right eyes, which is usually assumed to be 6.5 cm for an adult (Kim 2005). The desired position of the virtual object can be calculated by rearranging Equation (1) if the parallax and distance of the screen from the observer are known.