Aging effects in psychophysical foveal light detection sensitivity
... The relative sparse periods between the first three stages of sensitivity could be explained by the function measured and by the psychophysical paradigm used. Light detection could be considered the simplest perception function. Both the stimulus and the observer task are very basic which means a lo ...
... The relative sparse periods between the first three stages of sensitivity could be explained by the function measured and by the psychophysical paradigm used. Light detection could be considered the simplest perception function. Both the stimulus and the observer task are very basic which means a lo ...
optics
... noticed that a doctor had prescribed an adult dose of medicine for his then sixmonth old daughter that he was told could well have been fatal had she reached the end of the course. Our work might not be life and death, but checking each other’s work, and record keeping in particular, helps us get th ...
... noticed that a doctor had prescribed an adult dose of medicine for his then sixmonth old daughter that he was told could well have been fatal had she reached the end of the course. Our work might not be life and death, but checking each other’s work, and record keeping in particular, helps us get th ...
Anatomy and diseases of the uvea
... 4- Pigmented epithelium- two layers. The two layers are loosely attached to each other and there is a potential space between the 2 layers. In iridocyclitis there is adhesion of the iris to the lens. When a mydriatic is applied the posterior layer of pigment epithelium gets partly detached. This pr ...
... 4- Pigmented epithelium- two layers. The two layers are loosely attached to each other and there is a potential space between the 2 layers. In iridocyclitis there is adhesion of the iris to the lens. When a mydriatic is applied the posterior layer of pigment epithelium gets partly detached. This pr ...
Retinal fixation point location in the foveal avascular zone.
... fovea and foveola. These structures are highly specialized to maximize visual acuity. In the center of the anatomic fovea, the inner retinal layers down to the outer nuclear layer are displaced, forming a pit, the foveola, which contains the highest density of cones in the retina (147,000 cones per ...
... fovea and foveola. These structures are highly specialized to maximize visual acuity. In the center of the anatomic fovea, the inner retinal layers down to the outer nuclear layer are displaced, forming a pit, the foveola, which contains the highest density of cones in the retina (147,000 cones per ...
UPMC EYE CENTER
... developing the first whole-eye transplant program in the United States. Kia Washington, MD, a plastic surgeon, clinician-scientist, and expert on complex tissue allografting, is working to develop and refine a small animal model for whole-eye transplant that is adapted from a face transplant model s ...
... developing the first whole-eye transplant program in the United States. Kia Washington, MD, a plastic surgeon, clinician-scientist, and expert on complex tissue allografting, is working to develop and refine a small animal model for whole-eye transplant that is adapted from a face transplant model s ...
Accommodation Without Feedback Suggests Directional Signals
... and contrast is reduced for spectral components focused behind and in front of the retina. At low spatial frequencies (<0.5 c/d) defocus and aberrations have little or no effect on contrast of the image, but at higher spatial frequencies defocus reduces luminance contrast, and LCA alters the contras ...
... and contrast is reduced for spectral components focused behind and in front of the retina. At low spatial frequencies (<0.5 c/d) defocus and aberrations have little or no effect on contrast of the image, but at higher spatial frequencies defocus reduces luminance contrast, and LCA alters the contras ...
Retinal evaluation efficacy of a scanning laser ophthalmoscope
... using the optomap® Retinal Exam for screening was demonstrated by the fact that 44% more pathology was discovered by doctors through the optomap® Retinal Exam than with the digital retinal camera images. In their opinion, ultra-widefield scanning laser ophthalmoscopy and central digital photography ...
... using the optomap® Retinal Exam for screening was demonstrated by the fact that 44% more pathology was discovered by doctors through the optomap® Retinal Exam than with the digital retinal camera images. In their opinion, ultra-widefield scanning laser ophthalmoscopy and central digital photography ...
The Evolution of Eyes - Redwood Center for Theoretical Neuroscience
... about the distribution of light and dark in the surroundings. However, with only shadowingfrom the pigment cup to restrict the acceptance angle of individual receptors, the resolution is muchtoo poor for the eye to detect predators or prey, or to be involved in pattern recognition or the control of ...
... about the distribution of light and dark in the surroundings. However, with only shadowingfrom the pigment cup to restrict the acceptance angle of individual receptors, the resolution is muchtoo poor for the eye to detect predators or prey, or to be involved in pattern recognition or the control of ...
Scleral buckling biomaterials and implants for retinal detachment
... by a cryoprobe or laser to achieve local scar formation in order to seal the hole and to maintain the neurosensory retina attached to the RPE. The location and depth of indentation can be monitored during surgery, and it is securely maintained in the desired place by suturing the buckle in situ. Nor ...
... by a cryoprobe or laser to achieve local scar formation in order to seal the hole and to maintain the neurosensory retina attached to the RPE. The location and depth of indentation can be monitored during surgery, and it is securely maintained in the desired place by suturing the buckle in situ. Nor ...
Odd aberrations and double-pass measurements of retinal image
... imaging devices such as CCD arrays.8,9 The double-pass method offers several advantages over other methods for estimating retinal image quality. It is an objective method that is comfortable for the subject. It takes less than 10 min to obtain a complete twodimensional MTF with our experimental syst ...
... imaging devices such as CCD arrays.8,9 The double-pass method offers several advantages over other methods for estimating retinal image quality. It is an objective method that is comfortable for the subject. It takes less than 10 min to obtain a complete twodimensional MTF with our experimental syst ...
A New Safety Concern for Glaucoma Treatment - Laboratoire
... There is a growing body of evidence that BAK induces apoptosis, oxidative stress and inflammation on the ocular surface epithelia, unlike antiglaucoma active compounds that have been demonstrated to be safe for epithelial cells [6]. While the deleterious effects of BAK could be negligible for a shor ...
... There is a growing body of evidence that BAK induces apoptosis, oxidative stress and inflammation on the ocular surface epithelia, unlike antiglaucoma active compounds that have been demonstrated to be safe for epithelial cells [6]. While the deleterious effects of BAK could be negligible for a shor ...
Optical Lenses and Devices
... Eyes are our visual window to the world. They are complex structures that are capable of very high resolution, are extremely sensitive to light, capable even of detecting single photons, can give color and depth perception, and adjust to focus on objects from as close as 10 cm, in young eyes, to “in ...
... Eyes are our visual window to the world. They are complex structures that are capable of very high resolution, are extremely sensitive to light, capable even of detecting single photons, can give color and depth perception, and adjust to focus on objects from as close as 10 cm, in young eyes, to “in ...
Early morphogenesis of persistent hyperplastic tunica
... Optic Cup Throughout this study, the eyes at all ages were round to oval, double-layered structures. The average diameter values of the eyes of D25 up to D44 showed a steady increase from 0.284 to 3.7 mm (Table 1). Lens At D25, the lens vesicles consisted of epithelial cells, and had a rounded to so ...
... Optic Cup Throughout this study, the eyes at all ages were round to oval, double-layered structures. The average diameter values of the eyes of D25 up to D44 showed a steady increase from 0.284 to 3.7 mm (Table 1). Lens At D25, the lens vesicles consisted of epithelial cells, and had a rounded to so ...
the role of fixational eye movements in visual perception
... Structures within the eye. When these become visible they give rise to entoptic images. ...
... Structures within the eye. When these become visible they give rise to entoptic images. ...
Recurrent intraocular hemorrhage secondary to cataract wound
... A careful dilated retinal examination must be performed to rule out vitreous traction, retinal tear, or retinal vascular disease. Gonioscopy will ultimately provide the diagnosis, which reveals wound neovascula ...
... A careful dilated retinal examination must be performed to rule out vitreous traction, retinal tear, or retinal vascular disease. Gonioscopy will ultimately provide the diagnosis, which reveals wound neovascula ...
Fixational eye movements and motion perception
... Fig. 4. The visual jitter aftereffect that is contingent on various kinds of eye movement during the test period. The black arrows in the central unadapted regions schematically illustrate the direction of illusory motion, which is consistent with the direction of retinal image slip due to eye movem ...
... Fig. 4. The visual jitter aftereffect that is contingent on various kinds of eye movement during the test period. The black arrows in the central unadapted regions schematically illustrate the direction of illusory motion, which is consistent with the direction of retinal image slip due to eye movem ...
Progress in Measurement of Ocular Blood Flow and Age-Related Macular Degeneration
... represent the entire blood column. These methods are also commonly used in conjunction with ¯ow velocity measurements to calculate estimated volumetric blood ¯ow in retinal vessels. In order to measure vessel diameter in real units of length, individual eye magni®cation, the magni®cation of the came ...
... represent the entire blood column. These methods are also commonly used in conjunction with ¯ow velocity measurements to calculate estimated volumetric blood ¯ow in retinal vessels. In order to measure vessel diameter in real units of length, individual eye magni®cation, the magni®cation of the came ...
Characterization of the day-night variation of retinal melatonin
... values typical of mid-light. Pineal melatonin content responded similarly to the above lighting manipulations. Neither pinealectomy nor optic nerve transection had an effect on retina-pigment epithelium melatonin or its light-dark rhythm. We next examined the relative contributions of retinal and pi ...
... values typical of mid-light. Pineal melatonin content responded similarly to the above lighting manipulations. Neither pinealectomy nor optic nerve transection had an effect on retina-pigment epithelium melatonin or its light-dark rhythm. We next examined the relative contributions of retinal and pi ...
one vision2012 - University of Illinois College of Medicine at Chicago
... (AMD) affects more than 1.75 million people in the U.S. With a rapidly aging population, experts expect this number to reach 3 million by 2020. There is no cure. However, new treatments have emerged to offer improved prognosis, based on the discovery that a group of proteins in the body called vascu ...
... (AMD) affects more than 1.75 million people in the U.S. With a rapidly aging population, experts expect this number to reach 3 million by 2020. There is no cure. However, new treatments have emerged to offer improved prognosis, based on the discovery that a group of proteins in the body called vascu ...
Pax6 activity in the lens primordium is required for lens formation
... distal part of the OV invaginates to form the optic cup with the inner layer developing into the neuroretina (NR) and the outer layer forming the retinal pigmented epithelium (RPE; Pei and Rhodin 1970). The signals directing the coordinate growth of these two tissue components have been the subject ...
... distal part of the OV invaginates to form the optic cup with the inner layer developing into the neuroretina (NR) and the outer layer forming the retinal pigmented epithelium (RPE; Pei and Rhodin 1970). The signals directing the coordinate growth of these two tissue components have been the subject ...
Advancing a Model to Account for Abnormal Spatial
... SRP has been investigated in previous studies in normal [6-8] and pathological conditions [911]. In these surveys, the visual system is found to be affected by a mild unbalance in spatial relationship perception along the cardinal axes. In particular, normal subjects show better spatial relationship ...
... SRP has been investigated in previous studies in normal [6-8] and pathological conditions [911]. In these surveys, the visual system is found to be affected by a mild unbalance in spatial relationship perception along the cardinal axes. In particular, normal subjects show better spatial relationship ...
Pupillary responses in amblyopia - British Journal of Ophthalmology
... presence of a normal disc appearance. If the retina is considered at the site for the cause, then again several suggestions may be made. Retinal haemorrhages at birth could cause an undetectable retinal defect.2' However, from a series of babies followed up to an age at which visual acuity could be ...
... presence of a normal disc appearance. If the retina is considered at the site for the cause, then again several suggestions may be made. Retinal haemorrhages at birth could cause an undetectable retinal defect.2' However, from a series of babies followed up to an age at which visual acuity could be ...
Retina
The retina (/ˈrɛtɪnə/ RET-i-nə, pl. retinae, /ˈrɛtiniː/; from Latin rēte, meaning ""net"") is the third and inner coat of the eye which is a light-sensitive layer of tissue. The optics of the eye create an image of the visual world on the retina (through the cornea and lens), which serves much the same function as the film in a camera. Light striking the retina initiates a cascade of chemical and electrical events that ultimately trigger nerve impulses. These are sent to various visual centres of the brain through the fibres of the optic nerve.In vertebrate embryonic development, the retina and the optic nerve originate as outgrowths of the developing brain, so the retina is considered part of the central nervous system (CNS) and is actually brain tissue. It is the only part of the CNS that can be visualized non-invasively.The retina is a layered structure with several layers of neurons interconnected by synapses. The only neurons that are directly sensitive to light are the photoreceptor cells. These are mainly of two types: the rods and cones. Rods function mainly in dim light and provide black-and-white vision, while cones support daytime vision and the perception of colour. A third, much rarer type of photoreceptor, the intrinsically photosensitive ganglion cell, is important for reflexive responses to bright daylight.Neural signals from the rods and cones undergo processing by other neurons of the retina. The output takes the form of action potentials in retinal ganglion cells whose axons form the optic nerve. Several important features of visual perception can be traced to the retinal encoding and processing of light.