Videooculography (VOG) is an eye movement measurement method used in the objective evaluation of vestibulo-ocular reflexes (VOR). An important requirement of VOG is to accurately estimate pupil center and ocular torsion, irrespective of drooping eyelids, eyelashes, corneal reflection, and blinking. Finding the accurate center of the pupil is particularly important in three-dimensional VOG, sinc...

PURPOSE We studied whether pupil size affects the flicker electroretinograms (ERGs) recorded by RETeval, a new mydriasis-free full-field flicker ERG system. METHODS We studied 10 healthy subjects. The RETeval manufacturer claims that the system delivers a constant flash retinal illuminance by adjusting the flash luminance to compensate for changes in the pupil size. Two experiments were perfo...

When control of the pupil size is required, the simplest method is to use a physical artificial pupil or aperture that is placed in the spectacle plane. In some clinical applications (e.g., the potential acuity meter) an optical artificial pupil is imaged in the plane of the natural pupil by a Maxwellian view optical system. We compared visual performance with physical and Maxwellian artificial...

A video-based eye-tracker (e.g., the mobile Eyelink II or Eyelink Remote of SR research, Osgoode, Ontario, Canada) uses video cameras to record the eye position of human subjects, and hence, record pupil dilation and eye movements. The eyetracker puts a video cameras and infrared illuminators in front of the eye to record the position of the eye, cornea reflections, and the size of the pupil. U...

Camera-based eye trackers are the mainstay of eye movement research and countless practical applications of eye tracking. Recently, a significant impact of changes in pupil size on gaze position as measured by camera-based eye trackers has been reported. In an attempt to improve the understanding of the magnitude and population-wise distribution of the pupil-size dependent shift in reported gaz...

During recognition memory tests participants' pupils dilate more when they view old items compared to novel items. We sought to replicate this "pupil old/new effect" and to determine its relationship to participants' responses. We compared changes in pupil size during recognition when participants were given standard recognition memory instructions, instructions to feign amnesia, and instructio...

The changes in pupil size were recorded by infrared pupillographic methods in response to light flashes of different durations and intensities for a 13 degree 34 minute centrally fixated circular field. For such stimuli, the threshold intensities for (rod) vision and for the pupil response were found to be about the same. The response amplitudes were related to the logarithm of the flash energy...

We present a new technique for the correction of optical aberrations in wide-field fluorescence microscopy. Segmented-Pupil Image Interferometry (SPII) uses a liquid crystal spatial light modulator placed in the microscope's pupil plane to split the wavefront originating from a fluorescent object into an array of individual beams. Distortion of the wavefront arising from either system or sample...

The scaling of root mean square (RMS) wave aberration in an isometrically growing eye is investigated, along with changes due to measurements made at different relative pupil sizes. It is found that, relative to an initial state, if an eye expands in all directions by the factor k, and the wave aberration is then measured at a relative pupil size which has changed over the pupil size used for t...

We describe a simple and robust approach for characterizing the spatially varying pupil aberrations of microscopy systems. In our demonstration with a standard microscope, we derive the location-dependent pupil transfer functions by first capturing multiple intensity images at different defocus settings. Next, a generalized pattern search algorithm is applied to recover the complex pupil functi...