vision /vi·sion/ (vizh´un)
vision
vision (vizh´
n),
vision
Patient discussion about visioning.
1. the sense by which objects in the external environment are perceived by means of the light they give off or reflect.
2. the act of seeing.
3. an apparition; a subjective sensation of seeing not elicited by actual visual stimuli.
4. visual acuity.
achromatic vision monochromatic vision.
anomalous trichromatic vision defective color vision in which a person has all three cone pigments but one is deficient or anomalous but not absent.
binocular vision the use of both eyes together without diplopia.
central vision that produced by stimuli impinging directly on the macula retinae.
chromatic vision color v.
color vision
1. perception of the different colors making up the spectrum of visible light.
2. chromatopsia.
day vision visual perception in the daylight or under conditions of bright illumination.
dichromatic vision defective color vision in which one of the three cone pigments is missing; the two types are protanopia and deuteranopia.
direct vision central v.
double vision diplopia.
indirect vision peripheral v.
low vision impairment of vision such that there is significant visual handicap but also significant usable residual vision.
monochromatic vision complete color blindness; inability to discriminate hues, all colors of the spectrum appearing as neutral grays with varying shades of light and dark.
monocular vision vision with one eye.
multiple vision polyopia.
night vision visual perception in the darkness of night or under conditions of reduced illumination.
oscillating vision oscillopsia.
peripheral vision that produced by stimuli falling on areas of the retina distant from the macula.
solid vision , stereoscopic vision perception of the relief of objects or of their depth; vision in which objects are perceived as having three dimensions.
trichromatic vision
1. any ability to distinguish the three primary colors of light and mixtures of them.
2. normal color vision.
tunnel vision
1. that in which the visual field is severely constricted.
2. in psychiatry, restriction of psychological or emotional perception to a limited range.
vi·sion (v zh  n)n. 1. The faculty of sight; eyesight. 2. The manner in which an individual sees or conceives of something. |
vision
[vizh′ən]
Etymology: L, visus, vision
the capacity for sight.
vision (vizh´
n),n sight; the faculty of seeing.
vision, direct,
n the category of sight in which an image is focused directly on the macula of the retina. Also called
central vision.
central vision.
vision, field of,
n the portion of space that the fixed eye can see.
vision, indirect,
n 1. in dentistry, the capacity to see the treatment area by using a oral cavity mirror.
n 2. the category of sight in which an image is focused on an area of the retina other than the macula. Also called
peripheral vision.
n 2. the category of sight in which an image is focused on an area of the retina other than the macula. Also called
peripheral vision.
)
Indirect vision.
vision, stereoscopic,
n vision in which the visual fields of the two eyes are unified. Sensations from a common object received by the two eyes are superimposed, and as a result of the slight differences in the fields and the superimposition of the fields, the effects of depth and shape of the object are attained.
vision
the faculty of seeing; sight.
The basic components of vision are the eye itself, the visual center in the brain, and the optic nerve, which connects the two. Abnormalities of vision in animals can only be inferred by an assessment of the animal's response to a variety of visual stimuli. The commonly used tests of vision are the menace reflex test, the watching of a moving object and the obstacle test. These can all be performed in subdued light as a test for night blindness.
achromatic vision
vision characterized by lack of color vision.
aphakic vision
vision after lens removal.
binocular vision
the use of both eyes together, without diplopia.
central vision
that produced by stimulation of receptors in the fovea centralis.
day vision
visual perception in the daylight or under conditions of bright illumination.
double vision
diplopia.
half vision
hemianopia.
monocular vision
vision with one eye.
night vision
visual perception in the darkness of night or under conditions of reduced illumination.
panoramic vision
360° vision conferred on grazing herbivora by the lateral placement of their eyes.
peripheral vision
that produced by stimulation of receptors in the retina outside the macula lutea.
photopic vision
vision in bright illumination.
scotopic vision
vision in low illumination.
vision test
see visual acuity test.
vision (V)
1. The appreciation of differences in the external world, such as form, colour, position, etc. resulting from the stimulation of the retina by light.
2. See unaided visual acuity.
achromatic vision See achromatopsia.
alternating vision See contact lens.
ambient vision Vision mediated primarily by the peripheral retina and involved in spatial orientation and recognition of motion. See focal vision.
anomalous trichromatic vision See anomalous trichromatism.
binocular vision (BV) Condition in which both eyes contribute towards producing a percept which may or may not be fused into a single impression. See sensory fusion; monoblepsia; critical period; bar reading test; FRIEND test; hole in the hand test; Worth's four dot test; Worth's classification of binocular vision; binocular vision single zone of clear.
binocular single vision See single binocular vision.
blue vision See chromatopsia.
blurred vision Vision characterized by poor visual acuity or in which the edges of objects are indistinct. It may be due to uncorrected or poorly corrected ametropia or presbyopia, anomalies of the ocular media (e.g. cataract, corneal opacity, haemorrhage in the vitreous), amblyopia, excess lacrimation, spasm of accommodation, optic neuritis, angle-closure glaucoma, diabetes, multiple sclerosis, migraine, etc.
central vision Vision of objects formed on the foveola or the macula. See sensory fusion.
chromatic vision See colour vision.
colour vision (CV) Vision in which the colour sense is experienced. Syn. chromatic vision. See Hering's of colour vision theory; Young-Helmholtz theory.
daylight vision See photopic vision.
defective colour vision See defective colour vision.
deuteranomalous vision See deuteranomaly.
dichromatic vision See dichromatism.
distance vision (DV) Vision of objects situated either at infinity or more usually at some 5 or 6 m. See Snellen chart; near vision.
diurnal vision See photopic vision.
double v . See diplopia.
eccentric v . See eccentric fixation; peripheral vision.
entoptic v . See entoptic image.
extrafoveal vision See peripheral vision.
field of vision See visual field.
focal vision Vision mediated by, primarily, the macular area of the retina and involved in the examination and identification of objects. See ambient vision.
green v . See chromatopsia.
gun barrel v . See tunnel vision.
haploscopic vision Vision as obtained by looking in a haploscope.
indirect vision See peripheral vision.
industrial vision The branch of optometry concerned with vision and perception by the individual at work, the evaluation of visual performance in a given occupation, the prescribing of protective ocular devices and the determination of the optimum environment (e.g. illumination) to accomplish a visual task efficiently.
intermediate vision Vision of objects situated beyond 40 cm from the eye but closer than, say, 1.5 m. See distance vision; near vision.
island of vision A description of the visual field as a three-dimensional hill surrounded by a sea of darkness. Stimuli that fall within the island can be seen, whereas stimuli that fall outside the island cannot be seen. The height of the island represents the sensitivity of the eye, with the highest acuity at the top of the hill corresponding to foveal vision and declining progressively towards the periphery (when the eye is light-adapted). See visual field.
low vision Vision impairment even after correction by conventional lenses, resulting from either congenital anomalies or ocular diseases such as cataract, glaucoma, age-related macular degeneration, pathological myopia, trachoma, onchocerciasis, etc. The correction and rehabilitation of patients with low vision is achieved by special aids called low vision aids (LVA) such as a telescopic lens, and appropriate counselling (e.g. about illumination and reading distance). The criteria that the health authorities normally use to classify a person as having partial sight take into consideration not only the corrected visual acuity but also the extent of visual field loss (generally less than 20º). Syn. partial sight; subnormal vision.The World Health Organization (WHO) defines low vision as visual acuity less than 6/8 (20/60) and equal to or better than 3/60 (10/200) in the better eye with best correction. See low vision aids; blindness; bracketing; Bailey-Lovie chart; contrast sensitivity chart; clipover; deaf-blind; halogen lamp; cross-cylinder lens; telescopic lens; apparent magnification; relative distance magnification; relative size magnification; magnifier; Kestenbaum's rule; magnifying spectacles; pinhole spectacles; galilean telescope; Pepper test; typoscope; eccentric viewing.
mesopic vision Vision at intermediate levels between photopic and scotopic vision, and corresponding to luminances ranging from about 10−3 to 10 cd/m2. Syn. twilight vision.
monochromatic vision Synonym of monochro-matism. See monochromat.
monocular vision Vision of one eye only.
multiple vision See polyopia.
near vision (NV) Vision of objects situated 25-50 cm from either the eye, or more commonly the spectacle plane. See Jaeger test types; distance vision.
night vision; nocturnal vision See scotopic vision.
panoramic vision Vision of some animals whose eyes are located laterally so that the two visual fields overlap only slightly or are adjacent, thus providing vision over a much larger region of the environment than if the two lines of sight were aimed in the same direction.
peripheral vision Vision resulting from stimulation of the retina outside the fovea or macula. Syn. eccentric vision; extrafoveal vision; indirect vision. See sensory fusion; central vision.
photopic vision Vision at high levels of luminance (above 10 cd/m2) and resulting from the functioning of the cones. Syn. daylight vision; diurnal vision. See duplicity theory; differential threshold.
protanomalous vision See protanomaly.
red vision See chromatopsia.
vision science The scientific study of how the visual system contributes to an understanding of the environment by processing and interpreting the light stimulation to the eye. Various disciplines contribute to vision science including anatomy, biology, optics, physiology and psychology.
scotopic vision Vision at low levels of luminance, below about 10−3 cd/m2 and resulting from the functioning of the rods. Syn. night vision; nocturnal vision; scotopia. See duplicity theory.
vision screener An instrument used to measure various visual functions rapidly and inexpensively. There are various models, but most are modified stereoscopes with an internally illuminated set of targets and an optical system or variable target positioning to simulate either a near or far testing distance. Most of these instruments measure visual acuity, heterophoria, fusion, stereopsis, colour vision and visual field. See photorefraction.
simultaneous vision See contact lens.
single binocular vision (SBV) Condition in which both eyes contribute towards producing a single fused percept. See sensory fusion.
spatial vision See depth perception.
stereoscopic vision See stereopsis.
subnormal vision See low vision.
telescopic vision See tunnel vision.
vision therapy; vision training See visual training.
tritanomalous vision See tritanomaly.
tunnel vision Vision limited to the central part of the visual field as though one were looking through a hollow tube. It may be a symptom of hysteria, malingering, the final stage of either open-angle glaucoma or retinitis pigmentosa, etc. Syn. gun barrel vision; telescopic vision. See hysterical amblyopia; visual expander field.
twilight vision See mesopic vision.
Worth's classification of binocular vision For the purpose of visual rehabilitation, binocular vision is often classified into three grades: (1) simultaneous binocular vision (first-degree fusion or superimposition); (2) fusion (sensory fusion or second-degree fusion or flat fusion); (3) stereopsis (third-degree fusion). See sensory fusion; superimposition.
yellow vision See xanthopsia.
achromatic vision See achromatopsia.
alternating vision See contact lens.
ambient vision Vision mediated primarily by the peripheral retina and involved in spatial orientation and recognition of motion. See focal vision.
anomalous trichromatic vision See anomalous trichromatism.
binocular vision (BV) Condition in which both eyes contribute towards producing a percept which may or may not be fused into a single impression. See sensory fusion; monoblepsia; critical period; bar reading test; FRIEND test; hole in the hand test; Worth's four dot test; Worth's classification of binocular vision; binocular vision single zone of clear.
binocular single vision See single binocular vision.
blue vision See chromatopsia.
blurred vision Vision characterized by poor visual acuity or in which the edges of objects are indistinct. It may be due to uncorrected or poorly corrected ametropia or presbyopia, anomalies of the ocular media (e.g. cataract, corneal opacity, haemorrhage in the vitreous), amblyopia, excess lacrimation, spasm of accommodation, optic neuritis, angle-closure glaucoma, diabetes, multiple sclerosis, migraine, etc.
central vision Vision of objects formed on the foveola or the macula. See sensory fusion.
chromatic vision See colour vision.
colour vision (CV) Vision in which the colour sense is experienced. Syn. chromatic vision. See Hering's of colour vision theory; Young-Helmholtz theory.
daylight vision See photopic vision.
defective colour vision See defective colour vision.
deuteranomalous vision See deuteranomaly.
dichromatic vision See dichromatism.
distance vision (DV) Vision of objects situated either at infinity or more usually at some 5 or 6 m. See Snellen chart; near vision.
diurnal vision See photopic vision.
double v . See diplopia.
eccentric v . See eccentric fixation; peripheral vision.
entoptic v . See entoptic image.
extrafoveal vision See peripheral vision.
field of vision See visual field.
focal vision Vision mediated by, primarily, the macular area of the retina and involved in the examination and identification of objects. See ambient vision.
green v . See chromatopsia.
gun barrel v . See tunnel vision.
haploscopic vision Vision as obtained by looking in a haploscope.
indirect vision See peripheral vision.
industrial vision The branch of optometry concerned with vision and perception by the individual at work, the evaluation of visual performance in a given occupation, the prescribing of protective ocular devices and the determination of the optimum environment (e.g. illumination) to accomplish a visual task efficiently.
intermediate vision Vision of objects situated beyond 40 cm from the eye but closer than, say, 1.5 m. See distance vision; near vision.
island of vision A description of the visual field as a three-dimensional hill surrounded by a sea of darkness. Stimuli that fall within the island can be seen, whereas stimuli that fall outside the island cannot be seen. The height of the island represents the sensitivity of the eye, with the highest acuity at the top of the hill corresponding to foveal vision and declining progressively towards the periphery (when the eye is light-adapted). See visual field.
low vision Vision impairment even after correction by conventional lenses, resulting from either congenital anomalies or ocular diseases such as cataract, glaucoma, age-related macular degeneration, pathological myopia, trachoma, onchocerciasis, etc. The correction and rehabilitation of patients with low vision is achieved by special aids called low vision aids (LVA) such as a telescopic lens, and appropriate counselling (e.g. about illumination and reading distance). The criteria that the health authorities normally use to classify a person as having partial sight take into consideration not only the corrected visual acuity but also the extent of visual field loss (generally less than 20º). Syn. partial sight; subnormal vision.The World Health Organization (WHO) defines low vision as visual acuity less than 6/8 (20/60) and equal to or better than 3/60 (10/200) in the better eye with best correction. See low vision aids; blindness; bracketing; Bailey-Lovie chart; contrast sensitivity chart; clipover; deaf-blind; halogen lamp; cross-cylinder lens; telescopic lens; apparent magnification; relative distance magnification; relative size magnification; magnifier; Kestenbaum's rule; magnifying spectacles; pinhole spectacles; galilean telescope; Pepper test; typoscope; eccentric viewing.
mesopic vision Vision at intermediate levels between photopic and scotopic vision, and corresponding to luminances ranging from about 10−3 to 10 cd/m2. Syn. twilight vision.
monochromatic vision Synonym of monochro-matism. See monochromat.
monocular vision Vision of one eye only.
multiple vision See polyopia.
near vision (NV) Vision of objects situated 25-50 cm from either the eye, or more commonly the spectacle plane. See Jaeger test types; distance vision.
night vision; nocturnal vision See scotopic vision.
panoramic vision Vision of some animals whose eyes are located laterally so that the two visual fields overlap only slightly or are adjacent, thus providing vision over a much larger region of the environment than if the two lines of sight were aimed in the same direction.
peripheral vision Vision resulting from stimulation of the retina outside the fovea or macula. Syn. eccentric vision; extrafoveal vision; indirect vision. See sensory fusion; central vision.
photopic vision Vision at high levels of luminance (above 10 cd/m2) and resulting from the functioning of the cones. Syn. daylight vision; diurnal vision. See duplicity theory; differential threshold.
protanomalous vision See protanomaly.
red vision See chromatopsia.
vision science The scientific study of how the visual system contributes to an understanding of the environment by processing and interpreting the light stimulation to the eye. Various disciplines contribute to vision science including anatomy, biology, optics, physiology and psychology.
scotopic vision Vision at low levels of luminance, below about 10−3 cd/m2 and resulting from the functioning of the rods. Syn. night vision; nocturnal vision; scotopia. See duplicity theory.
vision screener An instrument used to measure various visual functions rapidly and inexpensively. There are various models, but most are modified stereoscopes with an internally illuminated set of targets and an optical system or variable target positioning to simulate either a near or far testing distance. Most of these instruments measure visual acuity, heterophoria, fusion, stereopsis, colour vision and visual field. See photorefraction.
simultaneous vision See contact lens.
single binocular vision (SBV) Condition in which both eyes contribute towards producing a single fused percept. See sensory fusion.
spatial vision See depth perception.
stereoscopic vision See stereopsis.
subnormal vision See low vision.
telescopic vision See tunnel vision.
vision therapy; vision training See visual training.
tritanomalous vision See tritanomaly.
tunnel vision Vision limited to the central part of the visual field as though one were looking through a hollow tube. It may be a symptom of hysteria, malingering, the final stage of either open-angle glaucoma or retinitis pigmentosa, etc. Syn. gun barrel vision; telescopic vision. See hysterical amblyopia; visual expander field.
twilight vision See mesopic vision.
Worth's classification of binocular vision For the purpose of visual rehabilitation, binocular vision is often classified into three grades: (1) simultaneous binocular vision (first-degree fusion or superimposition); (2) fusion (sensory fusion or second-degree fusion or flat fusion); (3) stereopsis (third-degree fusion). See sensory fusion; superimposition.
yellow vision See xanthopsia.
vision
Vox populi 1. The act of seeing 2. Visual acuity. See Binocular vision, Computer vision, Tunnel vision.
Patient discussion about visioning.
Q. What can you do to make your eye sight better? My eye sight isn’t that great. Is there anyway to improve it, like eating certain foods or drinking certain drinks?
A. Carrots
Very rich in Vitamin A. "Carrots are good for your eyesight", we were told as children and indeed around 500, 000 children worldwide are going blind every year because their diet and their mothers' breast milk does not contain sufficient amounts of vitamin A and Beta-carotene.
Beta carotene is a substance that is converted to Vitamin A in the human body. This vitamin helps transfer fat to energy. A 1/2 cup serving of cooked carrots contains four times the recommended daily intake of Vitamin A. Beta-carotene is also a powerful antioxidant effective in fighting against some forms of cancer.
For the entire list you can go to:
http://www.eyerobics.com.au/eyesight_food.html
Very rich in Vitamin A. "Carrots are good for your eyesight", we were told as children and indeed around 500, 000 children worldwide are going blind every year because their diet and their mothers' breast milk does not contain sufficient amounts of vitamin A and Beta-carotene.
Beta carotene is a substance that is converted to Vitamin A in the human body. This vitamin helps transfer fat to energy. A 1/2 cup serving of cooked carrots contains four times the recommended daily intake of Vitamin A. Beta-carotene is also a powerful antioxidant effective in fighting against some forms of cancer.
For the entire list you can go to:
http://www.eyerobics.com.au/eyesight_food.html
Q. Can depression cause your sight to narrow and your vision to be very spacey? Can depression cause your sight to narrow and your vision to be very spacey? If not what else may be the factor? If it did not seem to be that you were actually losing your vision and that you needed glasses.
A. Emotional depression originating from a person's response to life circumstances can squelch lymph circulation. Good lymph circulation is vital for good vision.
Also disease can affect lymph circulation and can cause physical depression and reduce vision.
Also disease can affect lymph circulation and can cause physical depression and reduce vision.
Q. very dark blood clots @ first sight of period? At first sight of period, instead of normal rosy spotting it's brownish spotting followed by small clots.
A. Hi Bonbolong.. I just need to ask you a few questions before I feel I can answer you to the best of my ability..Are you now, or have you ever been on birth control pills? How old are you? Have your periods always been like this? When I was young I had so many problems with my periods I wanted a hysterecomy. Of course at 14 years ols, my doctor wouldnt listen..LOL.. I would call your doctor just so he/she can assure you that you are ok..You said your blood was a browish color, I wouldnt worry about that, it is when the blood is black that means something is going on. DOnt worry abou t the clots, that is normal. Like I said, I had many problems when I was young, in fact my GYN had me on birth control at 14 years old. I hope I helped a little, but please get in touch with your doctor, it is amazing how much better you will feel when you find out you are fine
Shirley
Read more or ask a question about visioningShirley
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