scholarly journals A Neural Computation for Visual Acuity in the Presence of Eye Movements

PLoS Biology ◽  
2007 ◽  
Vol 5 (12) ◽  
pp. e331 ◽  
Author(s):  
Xaq Pitkow ◽  
Haim Sompolinsky ◽  
Markus Meister
Keyword(s):  
Visual Acuity ◽  
Eye Movements ◽  
Neural Computation

Self-motion-induced eye movements: effects on visual acuity and navigation

2005 ◽  
Vol 6 (12) ◽  
pp. 966-976 ◽  
Author(s):  
Dora E. Angelaki ◽  
Bernhard J. M. Hess
Keyword(s):  
Visual Acuity ◽  
Eye Movements ◽  
Self Motion

The effect of abnormal eye movements upon visual acuity

1996 ◽  
Vol 16 (3) ◽  
pp. 253-253
Author(s):  
Anita J. Simmers ◽  
Lyle S. Gray ◽  
Barry Winn
Keyword(s):  
Visual Acuity ◽  
Eye Movements

Introduction to the Six Eye Movement Systems and the Visual Fixation System

2008 ◽  
Author(s):  
Agnes Wong
Keyword(s):  
Visual Acuity ◽  
Eye Movements ◽  
High Resolution ◽  
Information Overload ◽  
Survival Rates ◽  
Large Field ◽  
Field Of Vision ◽  
Very High Spatial Resolution ◽  
Different Characteristics ◽  
The Brain

One main reason that we make eye movements is to solve a problem of information overload. A large field of vision allows an animal to survey the environment for food and to avoid predators, thus increasing its survival rate. Similarly, a high visual acuity also increases survival rates by allowing an animal to aim at a target more accurately, leading to higher killing rates and more food. However, there are simply not enough neurons in the brain to support a visual system that has high resolution over the entire field of vision. Faced with the competing evolutionary demands for high visual acuity and a large field of vision, an effective strategy is needed so that the brain will not be overwhelmed by a large amount of visual input. Some animals, such as rabbits, give up high resolution in favor of a larger field of vision (rabbits can see nearly 360°), whereas others, such as hawks, restrict their field of vision in return for a high visual acuity (hawks have vision as good as 20/2, about 10 times better than humans). In humans, rather than using one strategy over the other, the retina develops a very high spatial resolution in the center (i.e., the fovea), and a much lower resolution in the periphery. Although this “foveal compromise” strategy solves the problem of information overload, one result is that unless the image of an object of interest happens to fall on the fovea, the image is relegated to the low-resolution retinal periphery. The evolution of a mechanism to move the eyes is therefore necessary to complement this foveal compromise strategy by ensuring that an object of interest is maintained or brought to the fovea. To maintain the image of an object on the fovea, the vestibulo-ocular (VOR) and optokinetic systems generate eye movements to compensate for head motions. Likewise, the saccadic, smooth pursuit, and vergence systems generate eye movements to bring the image of an object of interest on the fovea. These different eye movements have different characteristics and involve different parts of the brain.

Establishing an Objective Measurement of Visual Acuity with a Computerised Optokinetic Nystagmus Suppression Test

2020 ◽  
Vol 237 (04) ◽  
pp. 502-505
Author(s):  
Noemie Schwob ◽  
Anja Palmowski-Wolfe
Keyword(s):  
Visual Acuity ◽  
Eye Movements ◽  
Optokinetic Nystagmus ◽  
Objective Measurement ◽  
Mean Difference ◽  
Alternative Option ◽  
Snellen Acuity ◽  
Suppression Test ◽  
Infrared Cameras ◽  
Acuity Test

Abstract Objective Investigating the correlation between subjective and objective VA (visual acuity) elicited with a newly developed computerised optokinetic nystagmus (OKN) suppression test (“SpeedWheel”) in adults. Methods SpeedWheel presented alternating black/white stripes moving horizontally across a LED screen. Seven VA steps were induced with Bangerter filters placed onto spectacle frames. Magnified eye movements were projected from infrared cameras inside the frames and displayed onto a smartphone. Dots whose size increased in logarithmic steps were superimposed to suppress OKN. Suppression of OKN resulted in the SpeedWheel acuity which was then correlated to Snellen acuity as measured with the Freiburg Acuity test. Results 28 eyes from 14 individuals were tested. FrACT-E correlated well to SpeedWheel (r: 0.89; p < 0.001). Snellen acuity was never lower than 0.14 LogMAR of SpeedWheel values. Bangerter filters showed greater mean difference to both methods indicating that this filter is not as predictable as suggested by the filter value. Conclusion SpeedWheel offers a fast (< 80 sec) and reliable alternative option to measure objective VA.

scholarly journals Fifteen-minute consultation: Preseptal and orbital cellulitis

2018 ◽  
Vol 104 (2) ◽  
pp. 79-83 ◽  
Author(s):  
Jonathan Adamson ◽  
Thomas Waterfield
Keyword(s):  
Emergency Department ◽  
Visual Acuity ◽  
Eye Movements ◽  
Colour Vision ◽  
Orbital Cellulitis ◽  
Initial Assessment ◽  
Management Options ◽  
Paediatric Emergency Department ◽  
Runny Nose ◽  
History Of

‘It is midnight and you are called to see a thirteen-year-old boy who has been brought to the paediatric emergency department with a 24-hour history of swelling and redness of his left eye. He has had a ‘runny nose’ for a couple of days. He is systemically well. His upper and lower lids are red and swollen such that his eye is not open fully, though you elicit normal eye movements when you open his eye. Pupils are equal and reactive with no afferent pupillary defect. Visual acuity and colour vision are normal on examination.’ In this article, we consider the approach to preseptal and orbital cellulitis in children including the initial assessment and management options.

scholarly journals Linking individual differences in fixational eye movements and visual acuity

2021 ◽  
Vol 21 (9) ◽  
pp. 2763
Author(s):  
Ashley Clark ◽  
Janis Intoy ◽  
Martina Poletti
Keyword(s):  
Visual Acuity ◽  
Individual Differences ◽  
Eye Movements ◽  
Fixational Eye Movements
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