Much of neurophysiology and vision science relies on careful measurement of a human or animal subject's gaze direction. Video-based eye trackers have emerged as an especially popular option for gaze tracking, because they are easy to use and are completely non-invasive. However, video eye trackers typically require a calibration procedure in which the subject must look at a series of points at ...

PURPOSE We investigate whether a structured probe beam that creates the beacon for use in a retinal imaging adaptive optics system can provide useful side effects. In particular we investigate whether a Bessel beam that is seen by the subject as a set of concentric rings has a dampening effect on fixation variations of the subject under observation. This calming effect would allow longer period...

Leiomyosarcoma of the iris is rare. Blodi (i964) doubted the occurrence of malignant myomata in the iris. Ashton (i964) described four cases of leiomyosarcoma as almost certainly malignant. The invasive properties of one of the neoplasms described were so obvious, that it was considered the most definitely malignant (Fig. i). The patient from whom this neoplasm was removed recently attended the...

We investigated the impact in spatial visual performance of the combined presence of different amounts of spherical aberration and intraocular scattering in the eye. In a group of subjects, contrast sensitivity at 6 cycles per degree was measured when viewing through holographic diffusers to produce different levels of scattering and with their spherical aberration simultaneously controlled usi...

We have extended the method of Alvarez [J. Am. Optom. Assoc. 49, 24 (1978)] to generate a variable magnitude of third-order spherical and/or coma aberration by using a combination of fourth-order plates with a magnification system. The technique, based on the crossed-cylinder aberroscope, is used to measure the wave-front aberration generated by the plates. The method has been applied to correc...

Patients with vestibular dysfunction have visual, perceptual, and postural deficits. While there is considerable evidence that a semicircular canal prosthesis that senses angular head velocity and stimulates canal ampullary nerves can improve vision by augmenting the vestibulo-ocular reflex, no information is available regarding the potential utility of a canal prosthesis to improve perceptual ...

Pupil size is correlated with a wide variety of important cognitive variables and is increasingly being used by cognitive scientists. Pupil data can be recorded inexpensively and non-invasively by many commonly used video-based eye-tracking cameras. Despite the relative ease of data collection and increasing prevalence of pupil data in the cognitive literature, researchers often underestimate t...

before you start • Provide privacy so that the patient can practice this procedure without others looking on. • Encourage the patient and reassure them that the procedure, although perhaps difficult at first, will become easier for him/her to manage alone. • Patients may wish to observe, by using a mirror, someone performing this procedure on them before attempting removal and insertion by them...

Corneal neovascularization causes deterioration of visual acuity and increases surface irregularities. Various techniques have been employed to help control the progression of corneal neovascularization; bevacizumab is a medication that targets the specific pathway of corneal neovascularization. The Boston Ocular Surface Prosthesis (BOSP) is a large diameter contact lens that aids in maintainin...

INTRODUCTION The loss of vestibular function cannot be restored in all cases, but a vestibular prosthesis can improve balance in many of these patients. Vestibular implant (VI) research has mostly focused on the detection of angular velocity of the cephalic movements through gyroscopes and stimulation of the three-ampulla crests of the semicircular canals in order to improve the vestibular ocul...