Visual impairment in the context of "Premature birth"

Louis Braille (/breɪl/ brayl; French: [lwi bʁɑj]; 4 January 1809 – 6 January 1852) was a French educator and the inventor of a reading and writing system named after him, braille, intended for use by visually impaired people. His system is used worldwide and remains virtually unchanged to this day.

Braille was blinded in one eye at the age of three. This occurred as a result from an accident with a stitching awl in his father's harness-making shop. Consequently, an infection set in and spread to both eyes, resulting in total blindness. At that time, there were not many resources in place for the blind, but he nevertheless excelled in his education and received a scholarship to France's Royal Institute for Blind Youth. While still a student there, he began developing a system of tactile code that could allow blind people to read and write quickly and efficiently. Inspired by a system invented by Charles Barbier, Braille's new method was more compact and lent itself to a range of uses, including music. He presented his work to his peers for the first time in 1824, when he was fifteen years old.

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.

The 1992 Paralympic Winter Games (French: Jeux paralympiques d'hiver de 1992) were the fifth Winter Paralympics. They were the first Winter Paralympics to be celebrated with the International Olympic Committee cooperation. They were also the first ever Paralympics or a Winter Parasports event held in France. They were held at the resort of Tignes as a support venue of the main host city Albertville, France, from 25 March to 1 April 1992. For the first time, demonstration events in Alpine and Nordic Skiing for athletes with an intellectual disability and Biathlon for athletes with a visual impairment were held.

Deafblindness is a condition of little or no useful hearing and little or no useful sight. According to the "Nordic definition", "deafblindness is a combined vision and hearing impairment of such severity that it is hard for the impaired senses to compensate for each other. Thus, deafblindness is a distinct disability." Different degrees of vision loss and auditory loss occur within each individual. Because of this inherent diversity, each deafblind individual's needs regarding lifestyle, communication, education, and work need to be addressed based on their degree of dual-modality deprivation, to improve their ability to live independently. In 1994, an estimated 35,000–40,000 United States residents were medically deafblind. Laura Bridgman was the first American deafblind person known to become well educated. Helen Keller was a well-known example of an educated deafblind individual. To further her lifelong mission to help the deafblind community to expand its horizons and gain opportunities, the Helen Keller National Center for Deaf-Blind Youths and Adults (also called the Helen Keller National Center or HKNC), with a residential training program in Sands Point, New York, was established in 1967 by an act of Congress.

The deafblind community has its own culture, comparable to those of the Deaf community. Members of the deafblind community have diverse backgrounds but are united by similar experiences and a shared, homogeneous understanding of what it means to be deafblind. Some deafblind individuals view their condition as a part of their identity.

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.

Cortical visual impairment (CVI) is a form of visual impairment that is caused by a brain problem rather than an eye problem. (The latter is sometimes termed "ocular visual impairment" when discussed in contrast to cortical visual impairment.) Some people have both CVI and a form of ocular visual impairment.

CVI is also sometimes known as cortical blindness, although most people with CVI are not totally blind. The term neurological visual impairment (NVI) covers both CVI and total cortical blindness. Delayed visual maturation, another form of NVI, is similar to CVI, except the child's visual difficulties resolve in a few months. Though the vision of a person with CVI may change, it rarely if ever becomes totally normal.

The Institut National des Jeunes Aveugles (INJA; National Institute for Blind Youth) is a special school for blind students in Paris, France. It is considered the first school for the blind in the Western world, and has served as a model for many subsequent schools for blind students.