1 Removing speckles is a key step for accurate pupil location in an iris recognition system. This paper proposed an algorithm to detect speckles in pupil area based on 2D Gabor filters first. Then the speckles were replaced selectively with the average intensity of a fixed square region. Finally, a novel evaluation index was introduced, which improved the pupil location accuracy rate of our for...

Rapid variations in cortical state during wakefulness have a strong influence on neural and behavioural responses and are tightly coupled to changes in pupil size across species. However, the physiological processes linking cortical state and pupil variations are largely unknown. Here we demonstrate that these rapid variations, during both quiet waking and locomotion, are highly correlated with...

Depressed individuals frequently display disruptions in selective attention, but the time course and specificity of these difficulties are not well-understood. To better understand the nature of attentional disruptions in depression, 28 healthy adults and 23 unmedicated depressed adults completed a Stroop color-naming task using a long inter-stimulus interval and pupil dilation was recorded as ...

Aiming at the fact that psychological state can be reflected by eye movement and pupil size, an affective assessment method based on the joint model of eye movement trajectory and pupil scaling was proposed in this paper. Firstly, the experimental apparatus was developed to capture and transmit the eye images. Secondly, multiple advanced image processing algorithms were synthetically adopted to...

The goal of educational methods is to allow the pupil the acquisition of knowledge. Even so, the way in which this aim is pursued originates four different currents of methods sorted by two criteria: (1) who leads the educational process and (2) requirement of pupil physical attendance. Regarding the former criterion, the process may be conducted either by the teacher—Teaching-Oriented Process—...

OBJECTIVE To investigate iris perfusion in patients with and without pupil ovalization after phakic intraocular lens implantation. METHODS Comparative retrospective randomized case series of 6 participants, each with a regular pupil, and 6 participants with pupil ovalization after phakic intraocular lens implantation for high myopia were included in the study. Indocyanine green angiography wa...

We present a 3D eye model fitting algorithm for use in gaze estimation, that operates on pupil ellipse geometry alone. It works with no user-calibration and does not require calibrated lighting features such as glints. Our algorithm is based on fitting a consistent pupil motion model to a set of eye images. We describe a non-iterative method of initialising this model from detected pupil ellips...

Video-based eye tracking is a valuable technique in various research fields. Numerous open-source eye tracking algorithms have been developed in recent years, primarily designed for general application with many different camera types. These algorithms do not, however, capitalize on the high frame rate of eye tracking cameras often employed in psychophysical studies. We present a pupil detectio...

The current study examined the extent to which pupillary responses (both pretrial baseline and phasic responses) would accurately track lapses of attention as predicted by theories of locus coeruleus norepinephrine (LC-NE) functioning. Participants performed a sustained attention task while pupil responses were continuously recorded. Periodically during the task, participants were presented wit...

We used a fast psychophysical procedure to determine the wave-front aberrations of the human eye in vivo. We measured the angular deviation of light rays entering the eye at different pupillary locations by aligning an image of a point source entering the pupil at different locations to the image of a fixation cross entering the pupil at a fixed location. We fitted the data to a Zernike series ...