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Computer and Human Vision Systems
Published in Sheila Anand, L. Priya, A Guide for Machine Vision in Quality Control, 2019
Six extraocular muscles control the movement of each eye: four rectus muscles and two oblique muscles. The medial, lateral, superior, and inferior rectus muscles move the eyeball horizontally and vertically. The superior and inferior obliques help in torsional movements like tilting the head to one side or looking up or down at an angle. The two oblique muscles of the eye are responsible for the rotation of the eye and assist the rectus muscles in their movements. The muscles of the eyes have also a role to play in the human vision system. The muscles perform a scanning function, called saccades, when looking at a large area and provide vital information to the brain. They also help in tracking moving objects in a visual field. The muscles of the eye also help in vergence, which is the simultaneous movement of both eyes to obtain or maintain a single binocular vision.
Anterior segment OCT
Published in Pablo Artal, Handbook of Visual Optics, 2017
Clinical applications can be enabled only for in vivo imaging that aims at visualization of the eye in its natural state. The movements of the eye facilitated by the extraocular muscles make the eyeball possible to be both shifted in all three directions and rotated. Additionally, some ocular structures such as the crystalline lens change their positions and shapes during accommodation. Since the eye is in a constant motion, imaging of the ocular structures requires the acquisition time to be short enough to minimize the impact of ocular motility. This can be realized by high imaging speed defined by high A-scan rate so that the data acquisition can be shortened. Consequently, the advances in imaging speed are critical for a precise and accurate extraction of quantitative parameters of the AS (Drexler et al., 2014). This issue can be also addressed by the implementation of specific algorithms for motion artifact removal in the post-processing (Maintz and Viergever, 1998, Potsaid et al., 2008, Ricco et al., 2009, Kraus et al., 2012). Clinical practice shows that the acquisition of OCT data should not exceed 2–3 s in order to assure both acceptable image quality and comfort of the patient during scanning.
Impact of Retinal Stimulation on Neuromodulation
Published in Yu Chen, Babak Kateb, Neurophotonics and Brain Mapping, 2017
A simplified viewpoint of visual output circuitry is to envision eye muscle movements as an end result after processing multisensory inputs. Eye muscles include the eyelids, pupils, and extraocular muscles. Movements can be quantified by the measurements of reaction time. In addition to cortically induced eye movements addressing eyesight, there are subcortical, reflexive eye movements induced by the brainstem and limbic system activity.
Influence of night vision goggles with white and green phosphor screens on selected parameters of the eye and fatigue
Published in Ergonomics, 2022
Karol Stasiak, Małgorzata Zyskowska, Ilona Głowinkowska, Krzysztof Kowalczuk, Rafał Lewkowicz
Correct stereoscopic vision results from three functions: simultaneous perception, fusion and correct spatial vision (Matthews 2001; Nęcka, Orzechowski, and Szymura 2013). The first function was preserved in our both tests; before and after the study, the participants had a visual acuity of 1.0 (20/20) in each eye. The function of correct fusion results from the proper functioning of the extraocular muscles, allowing the superimposition of the images from each eye into one. Correct stereoscopic vision is a function of the CNS and consists of the correct superimposition of images from both eyes and the creation of spatial vision. In the Butterfly stereotest examination, apart from the proper functioning of the extraocular muscles, it is also necessary to exhibit the correct function of intraocular muscles responsible for accommodation.