0_Wizard
So, is your eyesight 20/20? Do you have visual acuity?
Visual acuity (VA) commonly refers to the clarity of vision.
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Visual acuity
chosen_topic_0_Visual_acuity
Visual acuity
Visual acuity (VA) commonly refers to the clarity of vision. Visual acuity is dependent on optical and neural factors, i.e., (i) the sharpness of the retinal focus within the eye, (ii) the health and functioning of the retina, and (iii) the sensitivity of the interpretative faculty of the brain. A common cause of low visual acuity is refractive error (ametropia), or errors in how the light is refracted in the eyeball. Causes of refractive errors include aberrations in the shape of the eyeball, the shape of the cornea, and reduced flexibility of the lens. Too high or too low refractive error (in relation to the length of the eyeball) is the cause of nearsightedness (myopia) or farsightedness (hyperopia) (normal refractive status is referred to as emmetropia).
Visual impairment
Visual impairment, also known as vision impairment or vision loss, is a decreased ability to see to a degree that causes problems not fixable by usual means, such as glasses. Some also include those who have a decreased ability to see because they do not have access to glasses or contact lenses. Visual impairment is often defined as a best corrected visual acuity of worse than either 20/40 or 20/60. The term blindness is used for complete or nearly complete vision loss. Visual impairment may cause people difficulties with normal daily activities such as driving, reading, socializing, and walking.
Eye chart
An eye chart invented by Ferdinand Monoyer, is a chart used to measure visual acuity. Eye charts are often used by health care professionals, such as optometrists, physicians or nurses, to screen persons for vision impairment. Ophthalmologists, physicians who specialize in the eye, also use eye charts to monitor the visual acuity of their patients in response to various therapies such as medications or surgery. The chart is placed at a standardized distance away from the person whose vision is being tested. The person then attempts to identify the symbols on the chart, starting with the larger symbols and continuing with progressively smaller symbols until the person cannot identify the symbols.
B3 (classification)
B3 is a medical based Paralympic classification for blind sport. Competitors in this classification have partial sight, with visual acuity from 2/60 to 6/60. It is used by a number of blind sports including para-alpine skiing, para-Nordic skiing, blind cricket, blind golf, five-a-side football, goalball and judo. Some other sports, including adaptive rowing, athletics and swimming, have equivalents to this class. The B3 classification was first created by the IBSA in the 1970s, and has largely remained unchanged since despite an effort by the International Paralympic Committee (IPC) to move towards a more functional and evidence-based classification system.
Snellen chart
A Snellen chart is an eye chart that can be used to measure visual acuity. Snellen charts are named after the Dutch ophthalmologist Herman Snellen who developed the chart in 1862. Many ophthalmologists and vision scientists now use an improved chart known as the LogMAR chart. Snellen developed charts using symbols based in a 5×5 unit grid. The experimental charts developed in 1861 used abstract symbols. Snellen's charts published in 1862 used alphanumeric capitals in the 5×5 grid. The original chart shows A, C, E, G, L, N, P, R, T, 5, V, Z, B, D, 4, F, H, K, O, S, 3, U, Y, A, C, E, G, L, 2. The normal Snellen chart is printed with eleven lines of block letters.
Infant visual development
Infant vision concerns the development of visual ability in human infants from birth through the first years of life. The aspects of human vision which develop following birth include visual acuity, tracking, color perception, depth perception, and object recognition. Unlike many other sensory systems, the human visual system – components from the eye to neural circuits – develops largely after birth, especially in the first few years of life. At birth, visual structures are fully present yet immature in their potentials. From the first moment of life, there are a few innate components of an infant's visual system.
Stereopsis recovery
Stereopsis recovery, also recovery from stereoblindness, is the phenomenon of a stereoblind person gaining partial or full ability of stereo vision (stereopsis). Recovering stereo vision as far as possible has long been established as an approach to the therapeutic treatment of stereoblind patients. Treatment aims to recover stereo vision in very young children, as well as in patients who had acquired but lost their ability for stereopsis due to a medical condition. In contrast, this aim has normally not been present in the treatment of those who missed out on learning stereopsis during their first few years of life.
1_Apprentice
I have 20/20 eyesight, just had it checked last week. 
0_Wizard
The eye charts used were developed in 1862?
Snellen charts are named after the Dutch ophthalmologist Herman Snellen who developed the chart in 1862.
self_Tropical_cyclone_tracking_chart_1
Snellen chart
self_4_Snellen_chart
Eye chart
An eye chart invented by Ferdinand Monoyer, is a chart used to measure visual acuity. Eye charts are often used by health care professionals, such as optometrists, physicians or nurses, to screen persons for vision impairment. Ophthalmologists, physicians who specialize in the eye, also use eye charts to monitor the visual acuity of their patients in response to various therapies such as medications or surgery. The chart is placed at a standardized distance away from the person whose vision is being tested. The person then attempts to identify the symbols on the chart, starting with the larger symbols and continuing with progressively smaller symbols until the person cannot identify the symbols.
Marek Niedźwiecki
Marek Wojciech Niedźwiecki (born March 24, 1954 in Sieradz, Poland) is a Polish music journalist and radio anchor. Marek Niedźwiecki comes from a small city Szadek, with the population of about 2000, situated in central Poland in Łódź voivodeship, 36 km from Łódź. His father, Wojciech Niedźwiedzki (30.01.1912 – 24.12.1993), was a butcher by profession and worked as the manager in the local food industry cooperation "Samopomoc Chłopska". His mother Kazimiera (Kopeć) Niedźwiedzka (10.12.1926 – 25.04.2015) came from a farmers’ family residing in the village of Policzko and was a history teacher in Tadeusz Kościuszko Primary School in Szadek.
Astigmatism
Astigmatism is a type of refractive error in which the eye does not focus light evenly on the retina. This results in distorted or blurred vision at all distances. Other symptoms can include eyestrain, headaches, and trouble driving at night. If it occurs early in life it can result in amblyopia. The cause of astigmatism is unclear. It is believed to be partly related to genetic factors. The underlying mechanism involves an irregular curvature of the cornea or abnormalities in the lens of the eye. Diagnosis is by an eye exam. Three options exist for the treatment: glasses, contact lenses, and surgery.
Lea test
The LEA Vision Test System is a series of pediatric vision tests designed specifically for children who do not know how to read the letters of the alphabet that are typically used in eye charts. There are numerous variants of the LEA test which can be used to assess the visual capabilities of near vision and distance vision, as well as several other aspects of occupational health, such as contrast sensitivity, visual field, color vision, visual adaptation, motion perception, and ocular function and accommodation (eye). The first version of the LEA test was developed in 1976 by Finnish pediatric ophthalmologist Lea Hyvärinen, MD, PhD.
Tropical cyclone tracking chart
A tropical cyclone tracking chart is used by those within hurricane-threatened areas to track tropical cyclones worldwide. In the north Atlantic basin, they are known as hurricane tracking charts. New tropical cyclone information is available at least every six hours in the Northern Hemisphere and at least every twelve hours in the Southern Hemisphere. Charts include maps of the areas where tropical cyclones form and track within the various basins, include name lists for the year, basin-specific tropical cyclone definitions, rules of thumb for hurricane preparedness, emergency contact information, and numbers for figuring out where tropical cyclone shelters are open.
Norton's Star Atlas
Norton's Star Atlas is a set of 16 celestial charts, first published in 1910 and currently in its 20th edition under the editorship of Ian Ridpath. The "Star Atlas" covers the entire northern and southern sky, with accompanying reference information for amateur astronomers. The charts used in the first 17 editions of the "Atlas" were drawn by a British schoolmaster, Arthur Philip Norton (1876–1955), after whom the "Atlas" was named. Norton intended his star atlas to be used in conjunction with the highly popular observing handbooks written by the British amateurs William Henry Smyth and Thomas William Webb, and consequently most of the objects featured in those guidebooks were marked on the charts.
North Pacific right whale
The North Pacific right whale ("Eubalaena japonica") is a very large, thickset baleen whale species that is extremely rare and endangered. The Northeast Pacific population, which summers in the southeastern Bering Sea and Gulf of Alaska, may have no more than 40 animals. A western population that summers near the Commander Islands, the coast of Kamchatka, along the Kuril Islands and in the Sea of Okhotsk between it, is thought to number in the low hundreds. Before commercial whaling in the North Pacific (i.e. pre-1835) there were probably over 20,000 right whales in the region. The taking of right whales in commercial whaling has been prohibited by one or more international treaties since 1935.
1_Apprentice
Wow, I did not know that. That was a long time ago. One of the oldest professions. 