"a protein involved in retinal synapse formation or synaptic transmission. CSNB2 is caused by mutations in the gene ""CACNA1F"", which encodes a voltage-gated calcium channel Ca1.4. Not all congenital stationary night blindness (CSNB) are inherited in X-linked pattern. There are also autosomal dominant and recessive inheritance patterns for CSNB. The X-linked varieties of congenital stationary night blindness (CSNB) can be differentiated from the autosomal forms by the presence of myopia, which is typically absent in the autosomal forms. Patients with CSNB often have impaired night vision, myopia, reduced visual acuity, strabismus and nystagmus. Individuals with the complete form of CSNB"
"Nyctalopia Nyctalopia ( ), also called night-blindness, is a condition making it difficult or impossible to see in relatively low light. It is a symptom of several eye diseases. Night blindness may exist from birth, or be caused by injury or malnutrition (for example, vitamin A deficiency). It can be described as insufficient adaptation to darkness. The most common cause of nyctalopia is retinitis pigmentosa, a disorder in which the rod cells in the retina gradually lose their ability to respond to the light. Patients suffering from this genetic condition have progressive nyctalopia and eventually their daytime vision may also"
"– night blindness. Persistent deficiency gives rise to a series of changes, the most devastating of which occur in the eyes. Some other ocular changes are referred to as xerophthalmia. First there is dryness of the conjunctiva (xerosis) as the normal lacrimal and mucus-secreting epithelium is replaced by a keratinized epithelium. This is followed by the build-up of keratin debris in small opaque plaques (Bitot's spots) and, eventually, erosion of the roughened corneal surface with softening and destruction of the cornea (keratomalacia) and leading to total blindness. Other changes include impaired immunity (increased risk of ear infections, urinary tract infections,"
"Night vision Night vision is the ability to see in low-light conditions. Whether by biological or technological means, night vision is made possible by a combination of two approaches: sufficient spectral range, and sufficient intensity range. Humans have poor night vision compared to many animals, in part because the human eye lacks a tapetum lucidum. Night-useful spectral range techniques can sense radiation that is invisible to a human observer. Human vision is confined to a small portion of the electromagnetic spectrum called visible light. Enhanced spectral range allows the viewer to take advantage of non-visible sources of electromagnetic radiation (such"
"reduction in best night-time acuity due to the impairment of contrast sensitivity function (CSF) which is induced by intraocular light-scatter resulting from surgical intervention in the natural structural integrity of the cornea. Aulus Cornelius Celsus, writing ca. 30 AD, described night blindness and recommended an effective dietary supplement: ""There is besides a weakness of the eyes, owing to which people see well enough indeed in the daytime but not at all at night; in women whose menstruation is regular this does not happen. But success sufferers should anoint their eyeballs with the stuff dripping from a liver whilst roasting, preferably"
"Akinetopsia Akinetopsia (Greek: a for ""without"", kine for ""to move"" and opsia for ""seeing""), also known as cerebral akinetopsia or motion blindness, is a neuropsychological disorder in which a patient cannot perceive motion in their visual field, despite being able to see stationary objects without issue. There are varying degrees of akinetopsia: from seeing motion as a cinema reel to an inability to discriminate any motion. There is currently no effective treatment or cure for akinetopsia. Akinetopsia can be separated into two categories based on symptom severity and the amount the akinetopsia affects the patient's quality of life. Inconspicuous akinetopsia"
"senses. Night blindness, sometimes referred to as gravel, was occasionally documented during the American Civil War, particularly within the Confederate States of America. Like rheumatism, night blindness was viewed as a condition that could be easily faked or exaggerated, and initially sufferers were regarded with some suspicion. Some soldiers who reported symptoms of nyctalopia also presented with symptoms of scurvy, suggesting a fundamental cause of poor nutrition. Congenital stationary night blindness is also an ophthalmologic disorder in horses with leopard spotting patterns, such as the Appaloosa. It is present at birth (congenital), not sex-linked, non-progressive and affects the animal's vision"
"can be broken down as follows: Binasal hemianopsia Binasal hemianopsia (or binasal hemianopia) is the medical description of a type of partial blindness where vision is missing in the inner half of both the right and left visual field. It is associated with certain lesions of the eye and of the central nervous system, such as congenital hydrocephalus. In binasal hemianopsia, vision is missing in the inner (nasal or medial) half of both the right and left visual fields. Information from the nasal visual field falls on the temporal (lateral) retina. Those lateral retinal nerve fibers do not cross in"
"based on previously learned information. This is called visual memory. The inability to see is called blindness. Blindness may result from damage to the eyeball, especially to the retina, damage to the optic nerve that connects each eye to the brain, and/or from stroke (infarcts in the brain). Temporary or permanent blindness can be caused by poisons or medications. People who are blind from degradation or damage to the visual cortex, but still have functional eyes, are actually capable of some level of vision and reaction to visual stimuli but not a conscious perception; this is known as blindsight. People"
"Darkness Darkness, the polar opposite to brightness, is understood as a lack of illumination or an absence of visible light. Human vision is unable to distinguish color in conditions of either high brightness or darkness. In conditions with insufficient light levels, color perception ranges from achromatic to ultimately black. The emotional response to darkness has generated metaphorical usages of the term in many cultures. Referring to a time of day, complete darkness occurs when the Sun is more than 18° below the horizon, without the effects of twilight on the night sky. The perception of darkness differs from the mere"
"Macular degeneration Macular degeneration, also known as age-related macular degeneration (AMD or ARMD), is a medical condition which may result in blurred or no vision in the center of the visual field. Early on there are often no symptoms. Over time, however, some people experience a gradual worsening of vision that may affect one or both eyes. While it does not result in complete blindness, loss of central vision can make it hard to recognize faces, drive, read, or perform other activities of daily life. Visual hallucinations may also occur but these do not represent a mental illness. Macular degeneration"
"bind with opsin. Night blindness results. Night blindness caused by VAD has been associated with the loss of goblet cells in the conjunctiva, a membrane covering the outer surface of the eye. Goblet cells are responsible for secretion of mucus, and their absence results in xerophthalmia, a condition where the eyes fail to produce tears. Dead epithelial and microbial cells accumulate on the conjunctiva and form debris that can lead to infection and possibly blindness. Decreasing night blindness requires the improvement of vitamin A status in at-risk populations. Supplements and fortification of food have been shown to be effective interventions."
"Achromatopsia Achromatopsia (ACHM), also known as total color blindness, is a medical syndrome that exhibits symptoms relating to at least five conditions. The term may refer to acquired conditions such as cerebral achromatopsia, but it typically refers to an autosomal recessive congenital color vision condition, the inability to perceive color and to achieve satisfactory visual acuity at high light levels (typically exterior daylight). The syndrome is also present in an incomplete form which is more properly defined as dyschromatopsia. It is estimated to affect 1 in 30,000 live births worldwide. There is some discussion as to whether achromats can see"
"Binasal hemianopsia Binasal hemianopsia (or binasal hemianopia) is the medical description of a type of partial blindness where vision is missing in the inner half of both the right and left visual field. It is associated with certain lesions of the eye and of the central nervous system, such as congenital hydrocephalus. In binasal hemianopsia, vision is missing in the inner (nasal or medial) half of both the right and left visual fields. Information from the nasal visual field falls on the temporal (lateral) retina. Those lateral retinal nerve fibers do not cross in the optic chiasm. Calcification of the"
"This protein, found in the retina and the skin, exists in fractional percentages of the normal levels found in homozygous ""Lp/Lp"" horses and so compromises the basic chemical reaction for nerve impulse transmission. Nyctalopia Nyctalopia ( ), also called night-blindness, is a condition making it difficult or impossible to see in relatively low light. It is a symptom of several eye diseases. Night blindness may exist from birth, or be caused by injury or malnutrition (for example, vitamin A deficiency). It can be described as insufficient adaptation to darkness. The most common cause of nyctalopia is retinitis pigmentosa, a disorder"
"Oguchi disease Oguchi disease, also called congenital stationary night blindness, Oguchi type 1 or Oguchi disease 1, is an autosomal recessive form of congenital stationary night blindness associated with fundus discoloration and abnormally slow dark adaptation. Several mutations have been implicated as a cause of Oguchi disease. These include mutations in the arrestin gene or the rhodopsin kinase gene. The condition is more frequent in individuals of Japanese ethnicity. Oguchi disease present with nonprogressive night blindness since young childhood or birth with normal day vision, but they frequently claim improvement of light sensitivities when they remain for some time in"
"the Colorblind"". Footnotes Books Journals Achromatopsia Achromatopsia (ACHM), also known as total color blindness, is a medical syndrome that exhibits symptoms relating to at least five conditions. The term may refer to acquired conditions such as cerebral achromatopsia, but it typically refers to an autosomal recessive congenital color vision condition, the inability to perceive color and to achieve satisfactory visual acuity at high light levels (typically exterior daylight). The syndrome is also present in an incomplete form which is more properly defined as dyschromatopsia. It is estimated to affect 1 in 30,000 live births worldwide. There is some discussion as"
"Blind spot (vision) A blind spot, scotoma, is an obscuration of the visual field. A particular blind spot known as the ""physiological blind spot"", ""blind point"", or ""punctum caecum"" in medical literature, is the place in the visual field that corresponds to the lack of light-detecting photoreceptor cells on the optic disc of the retina where the optic nerve passes through the optic disc. Because there are no cells to detect light on the optic disc, the corresponding part of the field of vision is invisible. Some process in our brains interpolates the blind spot based on surrounding detail and"
"Bitemporal hemianopsia Bitemporal hemianopsia, also known as bitemporal heteronymous hemianopsia or bitemporal hemianopia, is the medical description of a type of partial blindness where vision is missing in the outer half of both the right and left visual field. It is usually associated with lesions of the optic chiasm, the area where the optic nerves from the right and left eyes cross near the pituitary gland. In bitemporal hemianopsia, vision is missing in the outer (temporal or lateral) half of both the right and left visual fields. Information from the temporal visual field falls on the nasal (medial) retina. The"
"incapable people leading other incapable people. Being blind to something means not understanding or being aware of it. A ""blind spot"" is an area where someone cannot see: for example, where a car driver cannot see because parts of his car's bodywork are in the way; metaphorically, a topic on which an individual is unaware of their own biases, and therefore of the resulting distortions of their own judgements (see Bias blind spot). A 2008 study tested the effect of using gene therapy to help restore the sight of patients with a rare form of inherited blindness, known as Leber's"
"Anophthalmia Anophthalmia, (Greek: ανόφθαλμος, ""without eye""), is the medical term for the absence of one or both eyes. Both the globe (human eye) and the ocular tissue are missing from the orbit. The absence of the eye will cause a small bony orbit, a constricted mucosal socket, short eyelids, reduced palpebral fissure and malar prominence. Genetic mutations, chromosomal abnormalities, and prenatal environment can all cause anophthalmia. Anophthalmia is an extremely rare disease and is mostly rooted in genetic abnormalities. It can also be associated with other syndromes. The most genetic based cause for anophthalmia is caused by the SOX2 gene."
"of plastic surgery and ocular prostheses. Anophthalmia Anophthalmia, (Greek: ανόφθαλμος, ""without eye""), is the medical term for the absence of one or both eyes. Both the globe (human eye) and the ocular tissue are missing from the orbit. The absence of the eye will cause a small bony orbit, a constricted mucosal socket, short eyelids, reduced palpebral fissure and malar prominence. Genetic mutations, chromosomal abnormalities, and prenatal environment can all cause anophthalmia. Anophthalmia is an extremely rare disease and is mostly rooted in genetic abnormalities. It can also be associated with other syndromes. The most genetic based cause for anophthalmia"
"of a he-goat, or failing that of a she-goat; and as well they should eat some of the liver itself."" Historically, nyctalopia, also known as moonblink, was a temporary night blindness believed to be caused by sleeping in moonlight in the tropics. In the French language, and have inverse meanings, the first naming the ability to see in the dark as well as in plain light, and the second the inability to do so. It is thought that this inversion from Latin happened during the 2nd century AD, even though the ancient greek νυκτάλωψ (""nuktálōps"") has been used in both"
"Blindsight Blindsight is the ability of people who are cortically blind due to lesions in their striate cortex, also known as primary visual cortex or V1, to respond to visual stimuli that they do not consciously see. The majority of studies on blindsight are conducted on patients who have the conscious blindness on only one side of their visual field. Following the destruction of the striate cortex, patients are asked to detect, localize, and discriminate amongst visual stimuli that are presented to their blind side, often in a forced-response or guessing situation, even though they do not consciously recognize the"
"as follows: In 1934, the American Medical Association adopted the following definition of blindness: Central visual acuity of 20/200 or less in the better eye with corrective glasses or central visual acuity of more than 20/200 if there is a visual field defect in which the peripheral field is contracted to such an extent that the widest diameter of the visual field subtends an angular distance no greater than 20 degrees in the better eye. The United States Congress included this definition as part of the Aid to the Blind program in the passed in 1935. In 1972, the Aid"
"Inattentional blindness Inattentional blindness, also known as perceptual blindness, is a psychological lack of attention that is not associated with any vision defects or deficits. It may be further defined as the event in which an individual fails to perceive an unexpected stimulus that is in plain sight. When it simply becomes impossible for one to attend to all the stimuli in a given situation, a temporary blindness effect can take place as a result; that is, individuals fail to see objects or stimuli that are unexpected and quite often salient. The term was coined by Arien Mack and Irvin"
"Flash blindness Flash blindness is a visual impairment during and following exposure to a light flash of extremely high intensity. The bright light overwhelms the eye and gradually fades, lasting anywhere from a few seconds to a few minutes. Flash blindness may also occur in everyday life. For example, the subject of a flash photograph can be temporarily flash blinded. This phenomenon is leveraged in non-lethal weapons such as flash grenades and laser dazzlers. Flash blindness is caused by bleaching (oversaturation) of the retinal pigment. As the pigment returns to normal, so too does sight. In daylight the eye's pupil"
"distance in darkness or poor weather. Such systems typically use infrared cameras, sometimes combined with active illumination techniques, to collect information that is then displayed to the driver. Such systems are currently offered as optional equipment on certain premium vehicles. Night vision Night vision is the ability to see in low-light conditions. Whether by biological or technological means, night vision is made possible by a combination of two approaches: sufficient spectral range, and sufficient intensity range. Humans have poor night vision compared to many animals, in part because the human eye lacks a tapetum lucidum. Night-useful spectral range techniques can"
"also surgical treatments for far-sightedness: The term ""hyperopia"" comes from Greek ὑπέρ ""hyper"" ""over"" and ὤψ ""ōps"" ""sight"" ( ὠπός ""ōpos""). Far-sightedness Far-sightedness, also known as hyperopia, is a condition of the eye in which light is focused behind, instead of on, the retina. This results in close objects appearing blurry, while far objects may appear normal. As the condition worsens, objects at all distances may be blurry. Other symptoms may include headaches and eye strain. People may also experience accommodative dysfunction, binocular dysfunction, amblyopia, and strabismus. The cause is an imperfection of the eyes. Often it occurs when the"
"be regained; however; prolonged vitamin A deficiency can lead to permanent visual loss if left untreated. Night blindness is especially prominent in developing countries due to malnutrition and therefore a lack of vitamin A in the diet. In developed countries night blindness has historically been uncommon due to adequate food availability; however, the incidence is expected to increase as obesity becomes more common. Increased obesity rates correspond to an increased number of bariatric surgeries, causing malabsorption of vitamin A in the human body. Adaptation (eye) In ocular physiology, adaptation is the ability of the eye to adjust to various levels"
"in the retina are also removed. Without light to the retina, the suprachiasmatic nucleus (SCN), located in the hypothalamus, is not cued each day to synchronize the circadian rhythm to the 24-hour social day, resulting in non-24 for many totally blind individuals. Non-24 is rare among visually impaired patients who retain at least some light perception. Researchers have found that even minimal light exposure at night can affect the body clock. People with this disorder might find it difficult to follow a regular clock scheme, as their biological clock can shift so much that they are sleepy during the day"
"Riddoch syndrome Riddoch syndrome (also known as the ""Riddoch phenomenon"") is a form of visual impairment often caused by lesions in the occipital lobe which limit the sufferer's ability to distinguish objects. Only moving objects in a blind field are visible, static ones being invisible to the patient. The moving objects are not perceived to have color or detail. The subject may only have awareness of the movement without visual perception of it (gnosanopsia), or the general shape of a moving object may be perceivable as a shadow like outline. At least one patient was able to use a rocking"
"Cortical blindness Cortical blindness is the total or partial loss of vision in a normal-appearing eye caused by damage to the brain's occipital cortex. Cortical blindness can be acquired or congenital, and may also be transient in certain instances. Acquired cortical blindness is most often caused by loss of blood flow to the occipital cortex from either unilateral or bilateral posterior cerebral artery blockage (ischemic stroke) and by cardiac surgery. In most cases, the complete loss of vision is not permanent and the patient may recover some of their vision (cortical visual impairment). Congenital cortical blindness is most often caused"