Buscar
Estás en modo de exploración. debe iniciar sesión para usar MEMORY

   Inicia sesión para empezar

level: Visual Perception

Questions and Answers List

level questions: Visual Perception

QuestionAnswer
To take up something - such as light, noise or energy - and not transmit it at allAbsorb
The process by which the eye changes its focus (in which the lens gets fatter as gaze is directed toward nearer objects)Accommodation
A disease associated with aging that affects the macula. It gradually destroys sharp central vision, making it difficult to read, drive and recognise faces. There are forms: Wet and DryAge-related macular degeneration (AMD)
A retinal cell found in the inner synaptic layer that makes synaptic contacts with bipolar cells, ganglion cells and other amacrine cellsAmacrine cell
The watery fluid in the anterior chamber of the eyeAqueous Humour
A visual defect caused by the unequal curving of one or more of the refractive surfaces of the eye, usually the corneaAstigmatism
A retinal cell that synapses with either rods or cones (not both) and with horizontal cells, and then passes the signals on to ganglion cellsBipolar cell
An opacity of the crystalline lensCataract
The light-catching part of the visual pigments of the retinaChromophore
A photoreceptor specialised for daylight vision, fine visual acuity and colourCone
The difference in luminance between an object and the background, or between lighter and darker parts of the same objectContrast
The transparent 'window' into the eyeballCornea
A Bipolar retinal cell whose processes are spread out to receive input from multiple conesDiffuse bipolar cell
A unit of measurement of the optic power of a lens. It is equal to the reciprocal of the focal length, in meters. A 2-ddiopter lens will bring parallel rays of light into focus at 0.5 meter (50cm)Diopter (D)
In reference to the retina, consisting of two parts: the rods and cones, which operate under different conditionsDuplex
The distance between the retinal image and the foveaEccentricity
The condition in which there is no refractive error, because the refractive power of the eye is perfectly matched to the length of the eyeballEmmetropia
An acoustic, electricl, electronic or optical device, instrument, computer program, or neuron that allows the passage of some range of parameters and blocks the passage of othersFilter
The distance between the lens (or mirror) and the viewed object, in metersFocal distance
A small pit located near the center of the macula and containing the highest concentation of cones, and no rods. It is the portion of the retina that produces the highest visual acuity and serves as the point of fixationFovea
The back layer of the retina: what the eye doctor sees through an ophthalmoscopeFundus
A retinal cell that receives visual information from photoreceptors via wo intermediate neuron types (bipolar cells and amacrine cells) and transmits information to the brain and midbrainGanglion cell
An electrical potential that can vary continuously in amplitudeGraded potential
A specialised retinal cell that contacts both photoreceptor and bipolar cellsHorizontal cell
The perceptual attribute of colours that enables them to be classed as similar to red, green, blue or something inbetweenHue
Farsightednes, a common condition in which light entering the eye is focused behind the retina and accommodation is required in order to see near objects clearlyHyperopia
A change in membrane potential such that the inner membrane surface becomes more negative than the outer membrane surfaceHyperpolarisation
A picture or likenessImage
the part of a photoreceptor that lies between the outer segment and the cell nucleusInner segment
The coloured part of the eye, consisting of a muscular diaphragm surrounding the pupile and regulating the light entering the eye by expanding and contracting the pupilIris
A neuron located between the magnocellular and parvocellular layers of the lateral geniculate nucleus.Koniocellular cell
Antagonistic neural interaction between adjacent regions of the retinaLateral inhibition
The lens inside the eye that enables the changing of focusLens
A ganglion cell resembling a little umbrella that receives excitatory input from diffuse bipolar cells and feeds the magnocellular layer of the lateral geniculate nucleusM ganglion cell
A photopigment, found in a class of photoreceptive retinal ganglion cells, that is sensitive to ambient lightMelanopsin
A small bipolar cell in the central retina that receives input from a single coneMidget bipolar cell
Nearsightedness, a common condition in which light entering the eye is focused in front of the retina and distant objects cannot be seen sharplyMyopia
A bipolar cell that hyperpolarises in response to an increase in light captured by the conesOFF Bipolar cell
A cell that increases firing in response to a decrease in light intensity in its receptive-field centerOFF Center cell
A bipolar cell that depolarises in response to an increase in light captured by the conesON Bipolar cell
A cell that increases firing in response to an increase in light intensity in its receptive-field centerON Center cell
An oscillation that travels through a medium by transferring energy from one particle or point to another without causing an permanent displacement of the mediumWave
The transparent fluid that fills the vitreous chamber in the posterior part of the eyeVitreous humor
The angle that an object subtends at the eyeVisual angle
The location where acons terminate at the synapse for transmission of information by the release of a chemical transmitterSynaptic terminal
A photoreceptor specialised for night visionRod
The visual pigment found in rodsRhodopsin
A progressive degeneration of the retina that affects night vision and peripheral vision. Commonly runs in families and can be caused by defects in a number of different genes that have recently been identifiedRetinitis pigmentosa (RP)
A very common disorder in which the image of the world is not clearly focused on the retina. The most common errors are: Myopia, Hyperopia, Astigmatism and PresbyopiaRefractive error
Literally 'old sight'. The age-related loss of accommodation, which makes it difficult to focus on near objectsPresbyopia
A quantum of visible light or other form of electromagnetic raiation demonstrating both particle and wave propertiesPhoton
Activation by lightPhotoactivation
A small ganglion cell that receives excitatory inputfrom single midget bipolar cells in the central retina and feeds the parvocellular layer of the lateral geniculate nucleusP Ganglion cell
The part of the photoreceptor that contains photopigment moleculesOuter Segment