The visual field is "that portion of space in which objects are visible at the same moment during steady fixation of the gaze in one direction"; in ophthalmology...

A visual field test is an eye examination that can detect dysfunction in central and peripheral vision which may be caused by various medical conditions...

Confrontation visual field testing is a test used in ophthalmology for rapid and gross detection of large-scale visual field problems. It is done by asking...

Humphrey field analyser (HFA) is a tool for measuring the human visual field that is commonly used by optometrists, orthoptists and ophthalmologists,...

brain include a visual cortex; the visual cortex in the left hemisphere receives signals from the right visual field, and the visual cortex in the right...

Lesions in that pathway cause a variety of visual field defects. In the visual system of human eye, the visual information processed by retinal photoreceptor...

(nicknamed blue-sky sprites) moving quickly along undulating pathways in the visual field, especially when looking into bright blue light such as the sky. The...

presented on the left or right visual hemifields. If a visual stimulus appears in the left visual field (LVF), the visual information is initially projected...

The visual system is the physiological basis of visual perception (the ability to detect and process light). The system detects, transduces and interprets...

Visual or vision impairment (VI or VIP) is the partial or total inability of visual perception. In the absence of treatment such as corrective eyewear...

flickering white, black, transparent, or colored dots across the whole visual field. Other common symptoms are palinopsia, enhanced entoptic phenomena, photophobia...

excluded in the visual field's definition. Humans have a slightly over 210-degree forward-facing horizontal arc of their visual field (i.e. without eye...

in specifying visual fields. According to IPS Perimetry Standards 1978 (2002): "Perimetry is the measurement of [an observer's] visual functions ... at...

peripheral vision, tunnel vision, occurs. Because of constant motion, the visual field of a driver is usually not stable. To monitor changes in our environment...

resolved in the very center of the visual field; it therefore does not indicate how larger patterns are recognized. Visual acuity alone thus cannot determine...

or hemianopia, is a loss of vision or blindness (anopsia) in half the visual field, usually on one side of the vertical midline. The most common causes...

Visual hierarchy, according to Gestalt psychology, is a pattern in the visual field wherein some elements tend to "stand out," or attract attention, more...

Visual agnosia is an impairment in recognition of visually presented objects. It is not due to a deficit in vision (acuity, visual field, and scanning)...

the receptive field ranges from the unidimensional chemical structure of odorants to the multidimensional spacetime of human visual field, through the...

seeing at night and decreasing peripheral vision (side and upper or lower visual field). As peripheral vision worsens, people may experience "tunnel vision"...

examination, followed by specific tests for visual acuity, pupil function, extraocular muscle motility, visual fields, intraocular pressure and ophthalmoscopy...

noticeable patterns are seen in the visual field. Most of the early glaucomatous changes are seen within the central visual field, mainly in Bjerrum's area, 10-20°...

vision at all,[citation needed] and in fact is hard to notice if the visual field is highly patterned, complex, or in motion.[citation needed] When active...

touches an object with only the left hand while receiving no visual cues in the right visual field; the patient will be unable to name the object, as each...

receives signals mainly from the right visual field and the right visual cortex mainly from the left visual field, although each cortex receives a considerable...

The equine eye is one of the largest of any land mammal. Its visual abilities are directly related to the animal's behavior; for example, it is active...

images can occur in any part of the visual field, and are rarely polymodal. One of the more enigmatic forms of visual hallucination is the highly variable...

correlated with CBS are a decrease of visual acuity, visual field loss, and elderly age. While characteristic features of visual hallucinations are not specifically...

central visual field. The grid was developed by Marc Amsler, a Swiss ophthalmologist. It is a diagnostic tool that aids in the detection of visual disturbances...

In visual perception, an optical illusion (also called a visual illusion) is an illusion caused by the visual system and characterized by a visual percept...