Search results for " Eye"

Changes of the eye optics after iris constriction☆

2010

Purpose: To evaluate the possible change in the optics of the human eye after iris constriction. Methods: Ocular aberrations were measured under natural viewing conditions in 26 eyes. The measured eyes fixated on a dim target while the contralateral eye was either occluded (so the measured eye had a large pupil) or highly illuminated (so the measured eye had a small pupil). The measured eyes fixated to a dim target placed 0.5 D beyond the subject’s far point. Zernike values obtained in both situations were compared within the same pupil diameter corresponding to the one obtained under the high illumination condition. Results: Significant variation in some aberration coefficients were found …

Diplostomum spathaceum metacercarial infection and colour change in salmonid fish

2004

Colour changes in two salmonid fish, the salmon (Salmo salar) and sea trout (S. trutta), were examined in relation to infection with the trematode Diplostomum spathaceum. This parasite had no effect on the rate of colour change in these fish, although species specific differences in colour adjustment times were observed. Increasing asymmetry in parasite numbers between the right and left eye, which could lead to the retention of vision in one eye, nevertheless tended to reduce the colour change time in salmon with moderate infection (P=0.08). This first experimental attempt to examine colour changes in fish in relation to eye fluke infections provides grounds for future investigations. The …

Opto-mechanical artificial eye with accommodative ability.

2015

The purpose of this study was to describe the design and characterization of a new opto-mechanical artificial eye (OMAE) with accommodative ability. The OMAE design is based on a second-pass configuration where a small source of light is used at the artificial retina plane. A lens whose focal length can be changed electronically was used to add the accommodation capability. The changes in the OMAE's aberrations with the lens focal length, which effectively changes the accommodative state of the OMAE, were measured with a commercial aberrometer. Changes in power and aberrations with room temperature were also measured. The OMAE's higher-order aberrations (HOAs) were similar to the ones of th…

<title>Modified crossed-cylinder aberroscope</title>

2001

We report a technique to estimate eye aberrations, based mainly on the subjective crossed-cylinder method. In order to obtain accurate coordinates of cross sections of the aberration distorted grid image on the retinal plane, needed in subjective methods, fusion of two images is used. The image seen by the eye under investigation is fused by the patient with a similar grid generated and reshaped in the appropriate way on the computer screen. The computer simulated image is viewed either by the second eye (in order to avoid eye rivalry and suppression processes, that are typical for such conditions, stimuli for both eyes are discontinuous and are displayed sequentially with a frequency of 50…

Simple Configuration Effects on Eye Movements in Horizontal Scanning Tasks

2015

When reading text, observers alternate periods of stable gaze (fixations) and shifts of gaze (saccades). An important debate in the literature concerns the processes that drive the control of these eye movements. Past studies using strings of letters rather than meaningful text ('z-reading') suggest that eye movement control during reading is, to a large extent, controlled by low-level image properties. These studies, however, have failed to take into account perceptual grouping processes that could drive these low-level effects. We here study the role of various grouping factors in horizontal scanning eye movements, and compare these to reading meaningful text. The results show that sequen…

Estimation of the mechanical properties of the eye through the study of its vibrational modes.

2017

Measuring the eye's mechanical properties in vivo and with minimally invasive techniques can be the key for individualized solutions to a number of eye pathologies. The development of such techniques largely relies on a computational modelling of the eyeball and, it optimally requires the synergic interplay between experimentation and numerical simulation. In Astrophysics and Geophysics the remote measurement of structural properties of the systems of their realm is performed on the basis of (helio-)seismic techniques. As a biomechanical system, the eyeball possesses normal vibrational modes encompassing rich information about its structure and mechanical properties. However, the integral a…

Time Unification on Local Binary Patterns Three Orthogonal Planes for Facial Expression Recognition

2019

International audience; Machine learning has known a tremendous growth within the last years, and lately, thanks to that, some computer vision algorithms started to access what is difficult or even impossible to perceive by the human eye. While deep learning based computer vision algorithms have made themselves more and more present in the recent years, more classical feature extraction methods, such as the ones based on Local Binary Patterns (LBP), still present a non negligible interest, especially when dealing with small datasets. Furthermore, this operator has proven to be quite useful for facial emotions and human gestures recognition in general. Micro-Expression (ME) classification is…

A new simple chromo-fluorogenic probe for NO2 detection in air.

2015

[EN] A new chromo-fluorogenic probe, consisting of a biphenyl derivative containing both a silylbenzyl ether and a N,N-dimethylamino group, for NO2 detection in the gas phase has been developed. A clear colour change from colourless to yellow together with an emission quenching was observed when the probe reacted with NO2. A limit of detection to the naked eye of about 0.1 ppm was determined and the system was successfully applied to the detection of NO2 in realistic atmospheric conditions.

Trace eyeblink conditioning and extinction contingent to hippocampal ripples in rabbits

2014

From monitoring to sharing of attention in dyadic interaction: The affordances of gaze data to better understand social aspects of remote collaborati…

2020

This paper aims to better understand the social aspects of collaborative problem solving (CPS) through studying joint attention behaviour (JAB) in an online game–like environment. To capture these behaviours and exemplify how ‘jointness’ is achieved in CPS in remote dyadic interaction, event-related measures are utilised based on the following multiple interaction data: (1) individuals’ gaze data from CPS task completion and (2) automatically generated log files (i.e. chats and actions) from dyadic interactions. The results give empirical evidence of the detached, individualistic attention experiences (i.e. monitoring and common attention) and of bidirectional relations (i.e. mutual and sha…