Classification and diversity of amblyopia.

Amblyopia is a developmental disorder that affects the spatial vision of one or both eyes in the absence of an obvious organic cause; it is associated with a history of abnormal visual experience during childhood. Subtypes have been defined based on the purported etiology, namely, strabismus (misaligned eyes) and/or anisometropia (unequal refractive error). Here we consider the usefulness of these subclassifications.

The effect of load on spatial attention depends on preview: Evidence from a reading study.

The spatio-temporal distribution of covert attention has usually been studied under unfamiliar tasks with static viewing. It is important to extend this work to familiar tasks such as reading where sequential eye movements are made. Our previous work with reading showed that covert spatial attention around the gaze location is affected by the fixated word frequency, or the processing load exerted by the word, as early as 40 ms into the fixation.

Both saccadic and manual responses in the amblyopic eye of strabismics are irreducibly delayed.

Abnormal early visual development can result in a constellation of neural and visual deficits collectively known as amblyopia. Among the many deficits, a common finding is that both saccadic and manual reaction times to targets presented to the amblyopic eye are substantially delayed when compared to the fellow eye or to normal eyes. Given the well-known deficits in contrast sensitivity in the amblyopic eye, a natural question is whether the prolonged reaction times are simply a consequence of reduced stimulus visibility.

When light hurts: Comparative Morphometry of Human Brainstem in Traumatic Photalgia.

Traumatic brain injury is an increasingly common affliction, although many of its serious repercussions are still underappreciated. A frequent consequence is the development of light-induced pain, or 'photalgia', which can often lead to prolonged debilitation. The mechanism underlying the sensitivity to light, however, remains unresolved.

Choosing a foveal goal recruits the saccadic system during smooth pursuit.

Models of smooth pursuit eye movements stabilize an object's retinal image, yet pursuit is peppered with small, destabilizing "catch-up" saccades. Catch-up saccades might help follow a small, spot stimulus used in most pursuit experiments, since fewer of them occur with large stimuli. However, they can return when a large stimulus has a small central feature.

Detection of Amblyopia Using Sweep VEP Vernier and Grating Acuity.

Purpose: Vernier and grating acuity can be measured with swept-parameter visual evoked potentials (sVEP). However, whether sVEP Vernier and grating acuities are comparable in predicting letter acuity has not been systematically evaluated. This study evaluated the validity and reliability of sVEP Vernier and grating acuity for the detection of amblyopia in adults.

Vision Rehabilitation is Part of AMD Care.

AMD does not just affect the retina. It severely affects people's lives. Paying attention to this aspect will only become more important as the population ages and more otherwise healthy individuals become affected.

AR4VI: AR as an Accessibility Tool for People with Visual Impairments.

Although AR technology has been largely dominated by visual media, a number of AR tools using both visual and auditory feedback have been developed specifically to assist people with low vision or blindness - an application domain that we term Augmented Reality for Visual Impairment (AR4VI). We describe two AR4VI tools developed at Smith-Kettlewell, as well as a number of pre-existing examples. We emphasize that AR4VI is a powerful tool with the potential to remove or significantly reduce a range of accessibility barriers.

Haptic aesthetics in the blind: A behavioral and fMRI investigation.

Understanding perception and aesthetic appeal of arts and environmental objects, what is appreciated, liked, or preferred, and why, is of prime importance for improving the functional capacity of the blind and visually impaired and the ergonomic design for their environment, which however so far, has been examined only in sighted individuals. This paper provides a general overview of the first experimental study of tactile aesthetics as a function of visual experience and level of visual deprivation, using both behavioral and brain imaging techniques. We investigated how blind people perceive 3D tactile objects, how they characterize them, and whether the tactile perception, and tactile shape preference (liking or disliking) and tactile aesthetic appreciation (judging tactile qualities of an object, such as pleasantness, comfortableness etc.

Evaluating Author and User Experience for an Audio-Haptic System for Annotation of Physical Models.

We describe three usability studies involving a prototype system for creation and haptic exploration of labeled locations on 3D objects. The system uses a computer, webcam, and fiducial markers to associate a physical 3D object in the camera's view with a predefined digital map of labeled locations ("hotspots"), and to do real-time finger tracking, allowing a blind or visually impaired user to explore the object and hear individual labels spoken as each hotspot is touched. This paper describes: (a) a formative study with blind users exploring pre-annotated objects to assess system usability and accuracy; (b) a focus group of blind participants who used the system and, through structured and unstructured discussion, provided feedback on its practicality, possible applications, and real-world potential; and (c) a formative study in which a sighted adult used the system to add labels to on-screen images of objects, demonstrating the practicality of remote annotation of 3D models.

JustPoint: Identifying Colors with a Natural User Interface.

People with severe visual impairments usually have no way of identifying the colors of objects in their environment. While existing smartphone apps can recognize colors and speak them aloud, they require the user to center the object of interest in the camera's field of view, which is challenging for many users. We developed a smartphone app to address this problem that reads aloud the color of the object pointed to by the user's fingertip, without confusion from background colors.

How a diverse research ecosystem has generated new rehabilitation technologies: Review of NIDILRR's Rehabilitation Engineering Research Centers.

Over 50 million United States citizens (1 in 6 people in the US) have a developmental, acquired, or degenerative disability. The average US citizen can expect to live 20% of his or her life with a disability. Rehabilitation technologies play a major role in improving the quality of life for people with a disability, yet widespread and highly challenging needs remain.

Illusory motion reveals velocity matching, not foveation, drives smooth pursuit of large objects.

When small objects move in a scene, we keep them foveated with smooth pursuit eye movements. Although large objects such as people and animals are common, it is nonetheless unknown how we pursue them since they cannot be foveated. It might be that the brain calculates an object's centroid, and then centers the eyes on it during pursuit as a foveation mechanism might.

A Subconscious Interaction between Fixation and Anticipatory Pursuit.

Ocular smooth pursuit and fixation are typically viewed as separate systems, yet there is evidence that the brainstem fixation system inhibits pursuit. Here we present behavioral evidence that the fixation system modulates pursuit behavior outside of conscious awareness. Human observers (male and female) either pursued a small spot that translated across a screen, or fixated it as it remained stationary.

Mind your crossings: Mining GIS imagery for crosswalk localization.

For blind travelers, finding crosswalks and remaining within their borders while traversing them is a crucial part of any trip involving street crossings. While standard Orientation & Mobility (O&M) techniques allow blind travelers to safely negotiate street crossings, additional information about crosswalks and other important features at intersections would be helpful in many situations, resulting in greater safety and/or comfort during independent travel. For instance, in planning a trip a blind pedestrian may wish to be informed of the presence of all marked crossings near a desired route.

The right way to kiss: directionality bias in head-turning during kissing.

Humans have a bias for turning to the right in a number of settings. Here we document a bias in head-turning to the right in adult humans, as tested in the act of kissing. We investigated head-turning bias in both kiss initiators and kiss recipients for lip kissing, and took into consideration differences due to sex and handedness, in 48 Bangladeshi heterosexual married couples.

Joint engagement in infants and its relationship to their visual impairment measurements.

Coordination of attention between a social partner and an external focus of shared interest, called joint engagement, is associated with positive developmental outcomes such as better language, socio-emotional, and theory of mind skills in sighted infants. Current measures of joint engagement rely on an infant's visual behaviors, making it difficult to study joint engagement in infants with low or no vision. In a naturalistic observational study, 20 infants with various levels of visual impairments - mean ages: 1.

Cortical sources of Vernier acuity in the human visual system: An EEG-source imaging study.

Vernier acuity determines the relative position of visual features with a precision better than the sampling resolution of cone receptors in the retina. Because Vernier displacement is thought to be mediated by orientation-tuned mechanisms, Vernier acuity is presumed to be processed in striate visual cortex (V1). However, there is considerable evidence suggesting that Vernier acuity is dependent not only on structures in V1 but also on processing in extrastriate cortical regions.

Assessment of Lower Doses of Intravitreous Bevacizumab for Retinopathy of Prematurity: A Phase 1 Dosing Study.

Importance: Intravitreous bevacizumab (0.25 to 0.625 mg) is increasingly used to treat type 1 retinopathy of prematurity (ROP), but there remain concerns about systemic toxicity.

Attention to Multiple Objects Facilitates Their Integration in Prefrontal and Parietal Cortex.

Selective attention is known to interact with perceptual organization. In visual scenes, individual objects that are distinct and discriminable may occur on their own, or in groups such as a stack of books. The main objective of this study is to probe the neural interaction that occurs between individual objects when attention is directed toward one or more objects.

Memory-guided drawing training increases Granger causal influences from the perirhinal cortex to V1 in the blind.

The perirhinal cortex (PRC) is a medial temporal lobe structure that has been implicated in not only visual memory in the sighted, but also tactile memory in the blind (Cacciamani & Likova, 2016). It has been proposed that, in the blind, the PRC may contribute to modulation of tactile memory responses that emerge in low-level "visual" area V1 as a result of training-induced cortical reorganization (Likova, 2012, 2015). While some studies in the sighted have indicated that the PRC is indeed structurally and functionally connected to the visual cortex (Clavagnier, Falchier, & Kennedy, 2004; Peterson, Cacciamani, Barense, & Scalf, 2012), the PRC's direct modulation of V1 is unknown-particularly in those who lack the visual input that typically stimulates this region.

Studying the Retinal Source of Photophobia by Facial Electroretinography.

Purpose: Photophobia is a debilitating clinical condition that disrupts the ability to use vision for everyday tasks in bright lighting conditions. The goal of the study is to develop a methodology to study the neural basis of photophobia and the contribution of the melanopic pathway to its etiology with differential chromatic responses by means of standard electroencephalographic recording equipment.

Methods: We introduce and validate the approach of recording wavelength-specific electroretinographic (ERG) responses from the face electrodes of the high-density whole-head electroencephalography recording system under light-adapted conditions.