• Infants
  • There are indications that in the course of the development of the visual system in infants, coarse stereopsis may develop before fine stereopsis and that coarse stereopsis guides the vergence movements which are needed in order for fine stereopsis to develop in a subsequent stage. (wikipedia.org)
  • apparatus
  • In clinical vision tests, hyperacuity has a special place because its processing is at the interfaces of the eye's optics, retinal functions, activation of the primary visual cortex and the perceptual apparatus. (wikipedia.org)
  • periods
  • Though there was a limited sample size, participants in both treatment groups showed improved visual acuity over 6 month periods, with no safety concerns. (wikipedia.org)
  • In fact, many planetaria today have what are called projection orreries, which project onto the dome a Sun with planets (usually limited to Mercury up to Saturn) going around it in something close to their correct relative periods. (wikipedia.org)
  • clinical
  • The initial visit will include a routine clinical eye examination, measurement of best-corrected visual acuity, indirect ophthalmoscopy, microperimetry, frequency-domain optical coherence tomography, Goldmann visual fields, fundus flavoprotein fluorescence (FPF) imaging, and fundus autofluorescence (FAF) and fundus photography. (clinicaltrials.gov)
  • lens
  • The patient was diagnosed with keratoconus at age 16, for which he used rigid contact lens in the left eye, with a best corrected visual acuity (VA) of 20/60. (hindawi.com)
  • IN can appear as an isolated ocular motor abnormality with nearly normal acuity or in association with a visual sensory disorder including opacities of the ocular media (cornea, lens, or vitreous) and functional abnormalities of the macula (albinism and aniridia) or optic nerve. (arvojournals.org)
  • The distance between the person's eyes and the testing chart is set so as to approximate "optical infinity" in the way the lens attempts to focus (far acuity), or at a defined reading distance (near acuity). (wikipedia.org)
  • In optics, the Airy disk (or Airy disc) and Airy pattern are descriptions of the best focused spot of light that a perfect lens with a circular aperture can make, limited by the diffraction of light. (wikipedia.org)
  • Even if one were able to make a perfect lens, there is still a limit to the resolution of an image created by such a lens. (wikipedia.org)
  • macular
  • This study will evaluate whether more sophisticated testing and analytic methodologies, including fundus autofluorescence (FAF) and a novel non-invasive method to measure retinal flavoprotein fluorescence (FPF) may be used to better predict Stargardt macular dystrophy progression and monitor treatment effects than conventional modalities such visual acuity and visual field. (clinicaltrials.gov)
  • optic nerve
  • 1 INS can occur by itself (idiopathic form) or in association with congenital or acquired defects in the visual sensory system (e.g., albinism, bilateral optic nerve hypoplasia, infantile cataract, aniridia, or various inherited types of retinal degeneration). (arvojournals.org)
  • These are sent to various visual centres of the brain through the fibres of the optic nerve. (wikipedia.org)
  • The optic nerve is a central tract of many axons of ganglion cells connecting primarily to the lateral geniculate body, a visual relay station in the diencephalon (the rear of the forebrain). (wikipedia.org)
  • The lesions leave behind some pigmentation, but visual acuity eventually improves even without any treatment (providing scarring doesn't interfere with the optic nerve). (wikipedia.org)
  • In rare cases, a patient may suffer permanent visual loss associated with lesions on their optic nerve. (wikipedia.org)
  • inner segment
  • Outer nuclear layer - cell bodies of rods and cones External limiting membrane - layer that separates the inner segment portions of the photoreceptors from their cell nucleus Layer of rods and cones - layer of rod cells and cone cells Retinal pigment epithelium - single layer of cuboidal cells (with extrusions not shown in diagram). (wikipedia.org)
  • Therefore
  • It allows the individual to determine the depth of objects in the central visual area (Panum's fusional area) and is therefore also called quantitative stereopsis. (wikipedia.org)
  • function
  • The result, θ = 4.56/D, with D in inches and θ in arcseconds is slightly narrower than calculated with the Rayleigh criterion: A calculation using Airy discs as point spread function shows that at Dawes' limit there is a 5% dip between the two maxima, whereas at Rayleigh's criterion there is a 26.3% dip. (wikipedia.org)
  • The upper cube size limit for software cubes is limited by the monitor's available pixels and what viewers find as acceptable which, in turn, is a function of their visual acuity. (wikipedia.org)
  • normal visual
  • Although there is some permanent damage to the corneal endothelium with decreased endothelial cell count and irregular shape, the remaining corneal endothelial cells usually recover with complete resolution of the corneal edema and a return to normal visual acuity. (wikipedia.org)
  • smallest
  • Regulatory provisions exist for extra-large 1,200 mm (47 in) signs with 400 mm (16 in) legend and 30 mm (1 1⁄4 in) border for use where sign visibility or reaction distance are limited, and the smallest permissible stop sign size for general usage is 600 mm (24 in) with a 200 mm (7.9 in) legend and 15 mm (⅝ in) border. (wikipedia.org)
  • angle
  • That size is specified as a visual angle, which is the angle, at the eye, under which the optotype appears. (wikipedia.org)
  • For 6/6 = 1.0 acuity, the size of a letter on the Snellen chart or Landolt C chart is a visual angle of 5 arc minutes (1 arc min = 1/60 of a degree). (wikipedia.org)
  • diffraction
  • The imaging system's resolution can be limited either by aberration or by diffraction causing blurring of the image. (wikipedia.org)
  • An optical system in which the resolution is no longer limited by imperfections in the lenses but only by diffraction is said to be diffraction limited. (wikipedia.org)
  • size
  • This hyperacuity, transcending by far the size limits set by the retinal 'pixels', depends on sophisticated information processing in the brain. (wikipedia.org)
  • The latter is the value used in the international definition of visual acuity: Acuity = 1/gap size [arc min] Acuity is a measure of visual performance and does not relate to the eyeglass prescription required to correct vision. (wikipedia.org)
  • The small size of typical 18th century orreries limited their impact, and towards the end of that century a number of educators attempted some larger scale simulations of the heavens. (wikipedia.org)
  • Software cube emulators are not subject to the physical restraints that impose a size limit on the hardware forms. (wikipedia.org)
  • higher
  • A sophisticated circuitry in the brain identifies the location of a visual feature by assessing the "center of gravity" of the light over several receptors, a task that can be accomplished with much higher precision than the resolution limit set by the receptor spacing. (wikipedia.org)
  • Indeed, a subject diagnosed as having 6/6 vision will often actually have higher visual acuity because, once this standard is attained, the subject is considered to have normal (in the sense of undisturbed) vision and smaller optotypes are not tested. (wikipedia.org)
  • sensory
  • Whether or not INS is associated with sensory system abnormalities, the continuous eye movements generally contribute to the visual deficit as a direct result of the inability to maintain stable fixation. (arvojournals.org)
  • The distinction between resolving power or acuity, literally sharpness, which depends on the spacing of the individual receptors through which the outside world is sampled, and the ability to identify individual locations in the sensory space is universal among modalities. (wikipedia.org)
  • vision
  • The best example of the distinction between acuity and hyperacuity comes from vision, for example when observing stars on a night sky. (wikipedia.org)
  • A reference value above which visual acuity is considered normal is called 6/6 vision, the USC equivalent of which is 20/20 vision: At 6 meters or 20 feet, a human eye with that performance is able to separate contours that are approximately 1.75 mm apart. (wikipedia.org)
  • In the expression 6/x vision, the numerator (6) is the distance in meters between the subject and the chart and the denominator (x) the distance at which a person with 6/6 acuity would discern the same optotype. (wikipedia.org)
  • state
  • Nevertheless behavioral acuity is remarkable close to its maximal value, given the immature state of young zebrafish larvae. (biomedcentral.com)
  • A simple and efficient way to state acuity is by solving the fraction to a decimal number. (wikipedia.org)
  • sets
  • Visual Acuity' sets the bar with dynamic spatial rendering applied to starbursting synths and rogue Garage patterns, while 'You Could Be Forgiven For Thinking That' casts of into sparser, more emotive deep space electronics. (boomkat.com)
  • This compartmentalization sets a limit to the decision whether an image came from a single or a double star (resolution). (wikipedia.org)
  • factor
  • The two-second rule may be the limiting factor governing the ACDA, when the speed of forward traffic is what limits the basic safe speed, and a primary hazard of collision could result from following any closer. (wikipedia.org)
  • Although
  • Linnaeus, Museum Adolphi Friderici Regis in reference to the red slender loris Although the term "lemur" was first intended for slender lorises, it was soon limited to the endemic Malagasy primates, which have been known as "lemurs" ever since. (wikipedia.org)
  • data
  • A method was developed to capture useful information from noisy data and validate the technique by showing meaningful relationships with visual functioning. (arvojournals.org)
  • found
  • A decreasing exponential relationship was found between visual acuity deficit and the NOFF, yielding a 0.75 logMAR deficit for the poorest NOFF and diminishing deficits with improving foveation. (arvojournals.org)
  • The formal Rayleigh criterion is close to the empirical resolution limit found earlier by the English astronomer W. R. Dawes who tested human observers on close binary stars of equal brightness. (wikipedia.org)