scholarly journals Performance of Complex Visual Tasks using Simulated Prosthetic Vision via Augmented-Reality Glasses

2019 ◽  
Author(s):  
Elton Ho ◽  
Jack Boffa ◽  
Daniel Palanker

AbstractPurposePhotovoltaic subretinal prosthesis is designed for restoration of central vision in patients with age-related macular degeneration (AMD). We investigated the utility of prosthetic central vision for complex visual tasks using augmented-reality (AR) glasses simulating reduced acuity, contrast and visual field.MethodsAR glasses with blocked central 20° of visual field included an integrated video camera and software which adjusts the image quality according to three user-defined parameters: resolution, corresponding to the equivalent pixel size of an implant, field of view, corresponding to the implant size, and number of contrast levels. The real-time processed video was streamed on a screen in front of the right eye. Nineteen healthy participants were recruited to complete visual tasks including vision charts, sentence reading, and face recognition.ResultsWith vision charts, letter acuity exceeded the pixel-sampling limit by 0.2 logMAR. Reading speed decreased with increasing pixel size and with reduced field of view (7-12°). In the face recognition task (4-way forced choice, 5° angular size) participants identified faces at >75% accuracy, even with 100 μm pixels and only 2 grey levels. With 60 μm pixels and 8 grey levels, the accuracy exceeded 97%.ConclusionsSubjects with simulated prosthetic vision performed slightly better than the sampling limit on the letter acuity tasks, and were highly accurate at recognizing faces, even with 100 μm/pixel resolution. These results indicate feasibility of the reading and face recognition using prosthetic central vision even with 100 μm pixels, and performance improves further with smaller pixels.

2019 ◽  
Vol 4 (4) ◽  
pp. 56-60
Author(s):  
M. M. Bikbov ◽  
O. I. Orenburkina ◽  
A. E. Babushkin

This review presents the characteristics and results of clinical studies of patients with age-related macular degeneration implanted with the developed for this purpose first macular IOL – intraocular macular telescope (IMT). This lens was designed specifically for patients with the most severe or terminal form of age-related macular degeneration and is designed for monocular implantation to provide central vision while maintaining peripheral vision of the paired eye, which is important for maintaining the balance and orientation of patients. This device allows patients to see both in dynamic and static situations in the near, intermediate and far ranges. The disadvantages of this lens are a decrease in the visual field and depth of focus (which excludes its bilateral implantation), the need for a large (10–12 mm) incision for implantation, which can cause an increase in corneal astigmatism and the risk of complications, in particular, the pupillary block with an increase in intraocular pressure. There are also difficulties in the study of the fundus after its implantation to assess the small changes in the macula or to identify possible postoperative complications after cataract surgery (macular oedema, etc.). Also after the implantation of this lens, there is need for special programs of visual rehabilitation. The patient’s commitment to the rehabilitation measures for the adaptation of the central visual field of the operated eye with the peripheral vision of the second eye is crucial for success of the IMT macular telescope implantation procedure.


2020 ◽  
Author(s):  
Michael C. Granovetter ◽  
Leah Ettensohn ◽  
Marlene Behrmann

AbstractThe left and right cerebral hemispheres are important for word and face recognition, respectively—a specialization that emerges over human development. But children who have undergone a hemispherectomy develop with only one hemisphere. The question is whether this preserved hemisphere, be it left or right, can support both word and face recognition. Here, a large sample of patients with childhood hemispherectomy and age-matched controls performed word- and face-matching tasks. Controls viewed stimuli either in one visual field (restricting initial processing to one hemisphere) or, like the patients, in central vision. Across word and face tasks, patients performed comparably to controls using primarily one hemisphere, but more poorly than controls viewing stimuli centrally with both hemispheres engaged. Additionally, patients showed deficits in low-level visual processing that may explain their word/face recognition deficits relative to controls. Altogether, the findings suggest that either hemisphere alone can support word and face recognition, albeit sub-optimally.


2018 ◽  
Author(s):  
Fatima Maria Felisberti

Visual field asymmetries (VFA) in the encoding of groups rather than individual faces has been rarely investigated. Here, eye movements (dwell time (DT) and fixations (Fix)) were recorded during the encoding of three groups of four faces tagged with cheating, cooperative, or neutral behaviours. Faces in each of the three groups were placed in the upper left (UL), upper right (UR), lower left (LL), or lower right (LR) quadrants. Face recognition was equally high in the three groups. In contrast, the proportion of DT and Fix were higher for faces in the left than the right hemifield and in the upper rather than the lower hemifield. The overall time spent looking at the UL was higher than in the other quadrants. The findings are relevant to the understanding of VFA in face processing, especially groups of faces, and might be linked to environmental cues and/or reading habits.


2020 ◽  
Vol 70 (12) ◽  
pp. 4244-4247

Leber hereditary optical neuropathy (LHON) is part of the class of optic neuropathies in which the mitochondrial function is impaired and is characterized by a painless, subacute, bilateral decrease of the central vision. We shall present the case of two brothers AM aged 31 and AT aged 40 who were diagnosed with LHON and whom we initiated treatment with idebenone 900 mg / day with monitoring at one month and 6 months. The mitochondrial DNA analysis demonstrated the existence of mutations 11778G>A for the mtND4 gene in both patients. Idebenone is a synthetic benzoquinone, analogue of ubiquinone. We found a slight but significant improvement in the visual field in patient AM at one month of treatment. We have not found another case in the literature with an improvement in vision so fast after this treatment, and this has led us to write this article. Keywords: Leber hereditary optical neuropathy (LHON), idebenone, mutations 11778G>A, mtND4 gene


Author(s):  
Eugene Hayden ◽  
Kang Wang ◽  
Chengjie Wu ◽  
Shi Cao

This study explores the design, implementation, and evaluation of an Augmented Reality (AR) prototype that assists novice operators in performing procedural tasks in simulator environments. The prototype uses an optical see-through head-mounted display (OST HMD) in conjunction with a simulator display to supplement sequences of interactive visual and attention-guiding cues to the operator’s field of view. We used a 2x2 within-subject design to test two conditions: with/without AR-cues, each condition had a voice assistant and two procedural tasks (preflight and landing). An experiment examined twenty-six novice operators. The results demonstrated that augmented reality had benefits in terms of improved situation awareness and accuracy, however, it yielded longer task completion time by creating a speed-accuracy trade-off effect in favour of accuracy. No significant effect on mental workload is found. The results suggest that augmented reality systems have the potential to be used by a wider audience of operators.


2019 ◽  
Vol 16 (4) ◽  
pp. 172988141986038
Author(s):  
Huang Yiqing ◽  
Wang Hui ◽  
Wei Lisheng ◽  
Gao Wengen ◽  
Ge Yuan

This article presented a cooperative mapping technique using a novel edge gradient algorithm for multiple mobile robots. The proposed edge gradient algorithm can be divided into four behaviors such as adjusting the movement direction, evaluating the safety of motion behavior, following behavior, and obstacle information exchange, which can effectively prevent multiple mobile robots falling into concave obstacle areas. Meanwhile, a visual field factor is constructed based on biological principles so that the mobile robots can have a larger field of view when moving away from obstacles. Also, the visual field factor will be narrowed due to the obstruction of the obstacle when approaching an obstacle and the obtained map-building data are more accurate. Finally, three sets of simulation and experimental results demonstrate the performance superiority of the presented algorithm.


Author(s):  
Georgianna Lin ◽  
Malcolm Haynes ◽  
Sarthak Srinivas ◽  
Pramod Kotipalli ◽  
Thad Starner

Where should a HWD be placed in a user's visual field? We present two studies that compare comfort, preference, task efficiency and accuracy for various HWD positions. The first study offsets a 9.2° horizontal field-of-view (FOV) display temporally (toward the ear) from 0° to 30° in 10° steps. 30° proves too uncomfortable while 10° is the most preferred position for a simple button-pushing game, corroborating results from previous single-task reading experiments. The second experiment uses a Magic Leap One to compare 10° x 10° FOV interfaces centered at line-of-sight, temporally offset 15° (center-right), inferiorly offset 15° (bottom-center), and offset in both directions (bottom-right) for an order picking task. The bottom-right position proved worst in terms of accuracy and several subjective metrics when compared to the line-of-sight position.


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