Blindness in the context of "Infection"

Braille (/ˈbreɪl/ BRAYL, French: [bʁaj] ) is a tactile writing system used by blind or visually impaired people. It can be read either on embossed paper or by using refreshable braille displays that connect to computers and smartphone devices. Braille can be written using a slate and stylus, a braille writer, an electronic braille notetaker or with the use of a computer connected to a braille embosser. For blind readers, braille is an independent writing system, rather than a code of printed orthography.

Braille is named after its creator, Louis Braille, a Frenchman who lost his sight as a result of a childhood accident. In 1824, at the age of fifteen, he developed the braille code based on the French alphabet as an improvement on night writing. He published his system, which subsequently included musical notation, in 1829. The second revision, published in 1837, was the first binary form of writing developed in the modern era.

Trachoma is an infectious disease caused by bacterium Chlamydia trachomatis. The infection causes a roughening of the inner surface of the eyelids. This roughening can lead to pain in the eyes, breakdown of the outer surface or cornea of the eyes, and eventual blindness. Untreated, repeated trachoma infections can result in a form of permanent blindness when the eyelids turn inward.

The bacteria that cause the disease can be spread by both direct and indirect contact with an affected person's eyes or nose. Indirect contact includes through clothing or flies that have come into contact with an affected person's eyes or nose. Children spread the disease more often than adults. Poor sanitation, crowded living conditions, and insufficient clean water and toilets also increase spread.

The slate and stylus are tools used by blind people to write text that they can read without assistance. Invented by Charles Barbier as the tool for writing letters that could be read by touch, the slate and stylus allow for a quick, easy, convenient and constant method of making embossed printing for Braille character encoding. Prior methods of making raised printing for the blind required a movable type printing press.

The visual system is the physiological basis of visual perception (the ability to detect and process light). The system detects, transduces and interprets information concerning light within the visible range to construct an image and build a mental model of the surrounding environment. The visual system is associated with the eye and functionally divided into the optical system (including cornea and lens) and the neural system (including the retina and visual cortex).

The visual system performs a number of complex tasks based on the image forming functionality of the eye, including the formation of monocular images, the neural mechanisms underlying stereopsis and assessment of distances to (depth perception) and between objects, motion perception, pattern recognition, accurate motor coordination under visual guidance, and colour vision. Together, these facilitate higher order tasks, such as object identification. The neuropsychological side of visual information processing is known as visual perception, an abnormality of which is called visual impairment, and a complete absence of which is called blindness. The visual system also has several non-image forming visual functions, independent of visual perception, including the pupillary light reflex and circadian photoentrainment.

Joint attention or shared attention is the shared focus of two individuals on an object. It is achieved when one individual alerts another to an object by means of eye-gazing, pointing or other verbal or non-verbal indications. An individual gazes at another individual, points to an object and then returns their gaze to the individual. Scaife and Bruner were the first researchers to present a cross-sectional description of children's ability to follow eye gaze in 1975. They found that most eight- to ten-month-old children followed a line of regard, and that all 11- to 14-month-old children did so. This early research showed it was possible for an adult to bring certain objects in the environment to an infant's attention using eye gaze.

Subsequent research demonstrates that two important skills in joint attention are following eye gaze and identifying intention. The ability to share gaze with another individual is an important skill in establishing reference. The ability to identify intention is important in a child's ability to learn language and direct the attention of others. Joint attention is important for many aspects of language development including comprehension, production and word learning. Episodes of joint attention provide children with information about their environment, allowing individuals to establish reference from spoken language and learn words. Socio-emotional development and the ability to take part in normal relationships are also influenced by joint attention abilities. The ability to establish joint attention may be negatively affected by deafness, blindness, and developmental disorders such as autism.

A screen reader is a form of assistive technology (AT) that renders text and image content as speech or braille output. Screen readers are essential to blind people, and are also useful to people who are visually impaired, illiterate or learning-disabled. Screen readers are software applications that attempt to convey what people with normal eyesight see on a display to their users via non-visual means, like text-to-speech, sound icons, or a braille device. They do this by applying a wide variety of techniques that include, for example, interacting with dedicated accessibility APIs, using various operating system features (like inter-process communication and querying user interface properties), and employing hooking techniques.

Microsoft Windows operating systems have included the Microsoft Narrator screen reader since Windows 2000, though separate products such as Freedom Scientific's commercially available JAWS screen reader and ZoomText screen magnifier and the free and open source screen reader NVDA by NV Access are more popular for that operating system. Apple Inc.'s macOS, iOS, and tvOS include VoiceOver as a built-in screen reader, while Google's Android provides the Talkback screen reader and its ChromeOS can use ChromeVox. Similarly, Android-based devices from Amazon provide the VoiceView screen reader. There are also free and open source screen readers for Linux and Unix-like systems, such as Speakup and Orca.

Nikola Altomanović (Serbian Cyrillic: Никола Алтомановић; died after 1395) was a 14th-century Serbian župan of the House of Vojinović. He ruled the areas from Rudnik, over Polimlje, Podrinje, east Herzegovina with Trebinje, reaching as far as Konavle and Dračevica, neighboring the Republic of Dubrovnik. He was defeated and blinded in Užice (fortress Užice) in 1373 by a coalition of his Serbian and Bosnian royals neighbors supported by the king of Hungary.

Measles (probably from Middle Dutch or Middle High German masel(e), meaning "blemish, blood blister") is a highly contagious, vaccine-preventable infectious disease caused by measles virus. Other names include morbilli, rubeola, 9-day measles, red measles, and English measles.

Symptoms usually develop 10–12 days after exposure to an infected person and last 7–10 days. Initial symptoms typically include fever, often greater than 40 °C (104 °F), cough, runny nose, and inflamed eyes. Small white spots known as Koplik spots may form inside the mouth two or three days after the start of symptoms. A red, flat rash which usually starts on the face and then spreads to the rest of the body typically begins three to five days after the start of symptoms. Common complications include diarrhea (in 8% of cases), middle ear infection (7%), and pneumonia (6%). These occur in part due to measles-induced immunosuppression. Less commonly, seizures, blindness, or inflammation of the brain may occur.

The Tragedy of King Lear, often shortened to King Lear, is a tragedy written by William Shakespeare in late 1605 or early 1606. Set in pre-Roman Britain, the play depicts the consequences of King Lear's love-test, in which he divides his power and land according to the praise of his daughters. The play is known for its dark tone, complex poetry, and prominent motifs concerning blindness and madness.

The earliest known performance was on Saint Stephen's Day in 1606. Modern editors derive their texts from three extant publications: the 1608 quarto (Q1), the 1619 quarto (Q2, unofficial and based on Q1), and the 1623 First Folio. The quarto versions differ significantly from the folio version.

Diabetes mellitus type 2, commonly known as type 2 diabetes (T2D), and formerly known as adult-onset diabetes, is a form of diabetes mellitus that is characterized by high blood sugar, insulin resistance, and relative lack of insulin. Common symptoms include increased thirst, frequent urination, fatigue and unexplained weight loss. Other symptoms include increased hunger, having a sensation of pins and needles, and sores (wounds) that heal slowly. Symptoms often develop slowly. Long-term complications from high blood sugar include heart disease, stroke, diabetic retinopathy, which can result in blindness, kidney failure, and poor blood flow in the lower limbs, which may lead to amputations. A sudden onset of hyperosmolar hyperglycemic state may occur; however, ketoacidosis is uncommon.

Type 2 diabetes primarily occurs as a result of obesity and lack of exercise. Some people are genetically more at risk than others. Type 2 diabetes makes up about 90% of cases of diabetes, with the other 10% due primarily to type 1 diabetes and gestational diabetes.

The Winter Paralympic Games is an international multi-sport event where athletes with physical disabilities compete in snow and ice sports. The event includes athletes with mobility impairments, amputations, blindness, and cerebral palsy. The Winter Paralympic Games are held every four years directly following the Winter Olympic Games and (since 1992) hosted in the same city. The International Paralympic Committee (IPC) oversees the Games. Medals are awarded in each event: with gold for first place, silver for second, and bronze for third, following the tradition that the Olympic Games began in 1904.

The Winter Paralympics began in 1976 in Örnsköldsvik, Sweden. Those Games were the first Paralympics that featured athletes other than those in wheelchairs. The Games have expanded and grown, including the Summer Paralympic Games, to become part of the largest international sporting event after the Olympics. Given their expansion, the need for a very specific classification system has arisen. This system has also given rise to controversy and opened the door for various forms of cheating, which has tainted the integrity of the Games.

Conversion disorder (CD) was a formerly diagnosed psychiatric disorder characterized by abnormal sensory experiences and movement problems during periods of high psychological stress. Individuals diagnosed with CD presented with highly distressing neurological symptoms such as numbness, blindness, paralysis, or convulsions, none of which were consistent with a well-established organic cause and could be traced back to a psychological trigger. CD is no longer a diagnosis in the WHO's ICD-11 or APA's DSM-5 and was superseded by functional neurologic disorder (FND), a similar diagnosis that notably removed the requirement for a psychological stressor to be present.

It was thought that these symptoms arise in response to stressful situations affecting a patient's mental health. Individuals diagnosed with conversion disorder have a greater chance of experiencing certain psychiatric disorders including anxiety disorders, mood disorders, and personality disorders compared to those diagnosed with neurological disorders.

The Moon System of Embossed Reading (commonly known as the Moon writing, Moon alphabet, Moon script, Moon type, or Moon code) is a writing system for the blind, using embossed symbols mostly derived from the Latin script (but simplified). It is claimed by its supporters to be easier to understand than braille, though it is mainly used by people who have lost their sight as adults, and thus already have knowledge of the shapes of letters.

A cataract is a cloudy area in the lens of the eye that leads to a decrease in vision of the eye. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colours, blurry or double vision, halos around light, trouble with bright lights, and difficulty seeing at night. This may result in trouble driving, reading and recognizing faces. Poor vision caused by cataracts may also result in an increased risk of falling and depression. In 2020 Cataracts caused 39.6% of all cases of blindness and 28.3% of visual impairment worldwide. Cataracts remain the single most common cause of global blindness.

Cataracts are most commonly due to aging but may also be due to trauma or radiation exposure, be present from birth or occur following eye surgery for other problems. Risk factors include diabetes, longstanding use of corticosteroid medication, smoking tobacco, prolonged exposure to sunlight and alcohol. In addition, poor nutrition, obesity, chronic kidney disease and autoimmune diseases have been recognized in various studies as contributing to the development of cataracts. Cataract formation is primarily driven by oxidative stress, which damages lens proteins, leading to their aggregation and the accumulation of clumps of protein or yellow-brown pigment in the lens. This reduces the transmission of light to the retina at the back of the eye, impairing vision. Additionally, alterations in the lens's metabolic processes, including imbalances in calcium and other ions, contribute to cataract development. Diagnosis is typically through an eye examination, with ophthalmoscopy and slit-lamp examination being the most effective methods. During ophthalmoscopy the pupil is dilated and the red reflex is examined for any opacities in the lens. Slit-lamp examination provides further details on the characteristics, location and extent of the cataract.

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. 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.

Macular degeneration typically occurs in older people, and is caused by damage to the macula of the retina. Genetic factors and smoking may play a role. The condition is diagnosed through a complete eye exam. Severity is divided into early, intermediate, and late types. The late type is additionally divided into "dry" and "wet" forms, with the dry form making up 90% of cases.

Diabetic retinopathy (also known as diabetic eye disease) is a medical condition in which damage occurs to the retina due to diabetes. It is a leading cause of blindness in developed countries and one of the leading causes of sight loss in the world, even though there are many new therapies and improved treatments for helping people living with diabetes.

Diabetic retinopathy affects up to 80 percent of those who have had both type 1 and type 2 diabetes for 20 years or more. In at least 90% of new cases, progression to more aggressive forms of sight-threatening retinopathy and maculopathy could be reduced with proper treatment and monitoring of the eyes. The longer a person has diabetes, the higher their chances of developing diabetic retinopathy. Each year in the United States, diabetic retinopathy accounts for 12% of all new cases of blindness. It is also the leading cause of blindness in people aged 20 to 64.