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This article is about the visual condition. For other uses, see Blindness (disambiguation).
Blindness
Classification and external resources
The Blind Girl (1856), a painting by John Everett Millais
ICD-10 H54.0, H54.1, H54.4
ICD-9 369

Blindness is the condition of lacking visual perception due to physiological or neurological factors. Sir John Everett Millais 1st Baronet, PRA ( June 8, 1829 &ndash August 13, 1896) was an English painter The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify Diseases The International Statistical Classification of Diseases and Related Health Problems 10th Revision ( ICD -10) is a coding of diseases and signs symptoms abnormal findings The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify Diseases The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. In Psychology, visual perception is the ability to interpret information from Visible light reaching the Eyes The resulting Perception is also Physiology (from Greek grc φύσις physis, "nature origin" and grc -λογία -logia) is the study of the mechanical physical

Various scales have been developed to describe the extent of vision loss and define "blindness. Vision loss or visual loss is the absence of vision where it existed before which can happen either acutely (i "[1] Total blindness is the complete lack of form and visual light perception and is clinically recorded as "NLP," an abbreviation for "no light perception. "[1] Blindness is frequently used to describe severe visual impairment with residual vision. Visual impairment or vision impairment is Vision loss that constitutes a significant limitation of visual capability resulting from Disease, Those described as having only "light perception" have no more sight than the ability to tell light from dark. A person with only "light projection" can tell the general direction of a light source.

In order to determine which people may need special assistance because of their visual disabilities, various governmental jurisdictions have formulated more complex definitions referred to as legal blindness. [2] In North America and most of Europe, legal blindness is defined as visual acuity (vision) of 20/200 (6/60) or less in the better eye with best correction possible. Eye examination Visual acuity (VA is acuteness or clearness of vision, especially form vision which is dependent on the sharpness of the retinal focus within the This means that a legally blind individual would have to stand 20 feet (6. 1 m) from an object to see it—with vision correction—with the same degree of clarity as a normally sighted person could from 200 feet (61 m). In many areas, people with average acuity who nonetheless have a visual field of less than 20 degrees (the norm being 180 degrees) are also classified as being legally blind. The term visual field is sometimes used as a Synonym to Field of view, though they do not designate the same thing This article describes the unit of angle For other meanings see Degree. Approximately ten percent of those deemed legally blind, by any measure, have no vision. The rest have some vision, from light perception alone to relatively good acuity. Low vision is sometimes used to describe visual acuities from 20/70 to 20/200. Low vision is a subspecialty within the professions of Optometry and Ophthalmology and Opticianry dealing with individuals who have less than normal vision [3]

By the 10th Revision of the WHO International Statistical Classification of Diseases, Injuries and Causes of Death, low vision is defined as visual acuity of less than 6/18, but equal to or better than 3/60, or corresponding visual field loss to less than 20 degrees, in the better eye with best possible correction. Blindness is defined as visual acuity of less than 3/60, or corresponding visual field loss to less than 10 degrees, in the better eye with best possible correction. [4][5]

It should be noted that blind people with undamaged eyes may still register light non-visually for the purpose of circadian entrainment to the 24-hour light/dark cycle. In Chronobiology, entrainment of a Circadian system is the alignment of its own period and phase to the period and phase of an external rhythm Light signals for this purpose travel through the retinohypothalamic tract (RHT), so a damaged optic nerve beyond where the RHT exits it is no hindrance. The Retinohypothalamic tract (RHT is a photic input pathway involved in Circadian rhythms.

Contents

Legal blindness

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 American Medical Association (AMA founded in 1847 and incorporated 1897 is the largest association of Physicians and Medical students in the United States [6]

The United States Congress included this definition as part of the Aid to the Blind program in the Social Security Act passed in 1935. The United States Congress is the bicameral Legislature of the federal government of the United States of America, consisting of two houses Social Security, in the United States currently refers to the federal Old-Age Survivors and Disability Insurance ( OASDI) program [6][7] In 1972, the Aid to the Blind program and two others combined under Title XVI of the Social Security Act to form the Supplemental Security Income program[8] which currently states:

An individual shall be considered to be blind for purposes of this title if he has central visual acuity of 20/200 or less in the better eye with the use of a correcting lens. Supplemental Security Income (or SSI) is a monthly stipend provided to aged (legally deemed to be 65 or older blind or disabled persons based on need paid by the United An eye which is accompanied by a limitation in the fields of vision such that the widest diameter of the visual field subtends an angle no greater than 20 degrees shall be considered for purposes of the first sentence of this subsection as having a central visual acuity of 20/200 or less. An individual shall also be considered to be blind for purposes of this title if he is blind as defined under a State plan approved under title X or XVI as in effect for October 1972 and received aid under such plan (on the basis of blindness) for December 1973, so long as he is continuously blind as so defined. [9]

Kuwait is one of many nations that share the same criteria for legal blindness. The State of Kuwait ( دولة الكويت IPA [dawlatt̪ alkuwajt̪]) is a sovereign Arab Emirate on the coast of the Persian Gulf, enclosed [10]

Epidemiology

In 1987, it was estimated that 598,000 people in the United States met the legal definition of blindness. [11] Of this number, 58% were over the age of 65. [11] In 1994-1995, 1. 3 million Americans reported legal blindness. [12]

In November 2004 article Magnitude and causes of visual impairment, the WHO estimated that in 2002 there were 161 million (about 2. 6% of the world population) visually impaired people in the world, of whom 124 million (about 2%) had low vision and 37 million (about 0. 6%) were blind. [13]

Causes of blindness

Serious visual impairment has a variety of causes:

Diseases

Most visual impairment is caused by disease and malnutrition. A disease is an abnormal condition of an organism that impairs bodily functions and can be deadly Malnutrition is a general term for a medical condition caused by an improper or insufficient diet. According to WHO estimates in 2002, the most common causes of blindness around the world are:

People in developing countries are significantly more likely to experience visual impairment as a consequence of treatable or preventable conditions than are their counterparts in the developed world. While vision impairment is most common in people over age 60 across all regions, children in poorer communities are more likely to be affected by blinding diseases than are their more affluent peers.

The link between poverty and treatable visual impairment is most obvious when conducting regional comparisons of cause. Poverty (also called penury) is deprivation of common necessities that determine the quality of life including food clothing shelter and safe Drinking water, and Most adult visual impairment in North America and Western Europe is related to age-related macular degeneration and diabetic retinopathy. Western Europe at its most general meaning means 'all the countries in the West of Europe ' While both of these conditions are subject to treatment, neither can be cured. Another common cause is retinopathy of prematurity. Retinopathy of prematurity ( ROP) previously known as retrolental fibroplasia (RLF is a disease of the Eye that affects prematurely born babies

In developing countries, wherein people have shorter life expectancies, cataracts and water-borne parasites—both of which can be treated effectively—are most often the culprits (see River blindness, for example). Onchocerciasis ( or /ˈɒnkoʊsɝːˈkaɪəsɨs/ also known as river blindness, is the world's second leading infectious cause of Blindness. Of the estimated 40 million blind people located around the world, 70–80% can have some or all of their sight restored through treatment.

In developed countries where parasitic diseases are less common and cataract surgery is more available, age-related macular degeneration, glaucoma, and diabetic retinopathy are usually the leading causes of blindness. Cataract surgery is the removal of the lens of the Eye (also called "crystalline" that has developed an opacification which is referred to as a [14]

Abnormalities and injuries

Eye injuries, most often occurring in people under 30, are the leading cause of monocular blindness (vision loss in one eye) throughout the United States. The United States of America —commonly referred to as the Injuries and cataracts affect the eye itself, while abnormalities such as optic nerve hypoplasia affect the nerve bundle that sends signals from the eye to the back of the brain, which can lead to decreased visual acuity. Optic nerve hypoplasia is a medical condition that results in underdevelopment of the Optic nerves Development of the optic nerve During the second month of

People with injuries to the occipital lobe of the brain can, despite having undamaged eyes and optic nerves, still be legally or totally blind. The occipital lobe is the visual processing center of the Mammalian Brain containing most of the anatomical region of the Visual cortex. The brain is the center of the Nervous system in animals All Vertebrates and the majority of Invertebrates have a brain The optic nerve, also called cranial nerve II, is the Nerve that transmits visual information from the Retina to the Brain.

Genetic defects

People with albinism often suffer from visual impairment to the extent that many are legally blind, though few of them actually cannot see. Albinism (from Latin albus, "white" see extended etymology) is a form of hypopigmentary Congenital disorder, Leber's congenital amaurosis can cause total blindness or severe sight loss from birth or early childhood. Leber's congenital amaurosis (LCA is a rare inherited eye disease that appears at birth or in the first few months of life and affects around 1 in 80000

Recent advances in mapping of the human genome have identified other genetic causes of low vision or blindness. Genetic linkage occurs when particular genetic loci or Alleles for genes are inherited jointly The human genome is the Genome of Homo sapiens, which is stored on 23 chromosome pairs Low vision is a subspecialty within the professions of Optometry and Ophthalmology and Opticianry dealing with individuals who have less than normal vision One such example is Bardet-Biedl syndrome. Laurence-Moon-Biedl syndrome and Laurence-Moon-Biedl-Bardet redirect here

Poisoning

A small portion of all cases of blindness are caused by the intake of certain chemicals. A well-known example is methanol,[15] found in methylated spirits, which are sometimes used by alcoholics as a cheap substitute for regular alcoholic beverages. Methanol, also known as methyl alcohol, carbinol, wood alcohol, wood naphtha or wood spirits, is a Chemical compound Denatured alcohol is Ethanol which has been rendered toxic or otherwise undrinkable and in some cases dyed Alcoholism is a term with multiple and sometimes conflicting definitions

Willful actions

Blinding has been used as an act of vengeance and torture in some instances, to deprive a person of a major sense by which they can navigate or interact within the world, act fully independently, and be aware of events surrounding them. Torture, according to the United Nations Convention Against Torture, is "any act by which severe pain or suffering, whether physical or mental is intentionally An example from the classical realm is Oedipus, who gouges out his own eyes after realizing that he fulfilled the awful prophecy spoken of him. Oedipus (pronounced /ˈɛdəpəs/ in American English or /ˈiːdəpəs/ in British English; Greek: Oidípous meaning "swollen-footed"

Treatments

A 2008 study published in the New England Journal of Medicine[16] tested the effect of using gene therapy to help restore the sight of patients with a rare form of inherited blindness, known as Leber Congenital Amaurosis or LCA. Leber Congenital Amaurosis damages the light receptors in the retina and usually begins affecting sight in early childhood, with worsening vision until complete blindness around the age of 30.

The study used a common cold virus to deliver a normal version of the gene called RPE65 directly into the eyes of affected patients. Remarkably all 3 patients aged 19, 26 and 26 responded well to the treatment and reported improved vision following the procedure. [17] Due to the age of the patients and the degenerative nature of LCA the improvement of vision in gene therapy patients is encouraging for researchers. It is hoped that gene therapy may be even more effective in younger LCA patients who have experienced limited vision loss as well as in other blind or partially blind individuals.

Adaptive techniques

A tactile feature on a Canadian banknote.
A tactile feature on a Canadian banknote. The Canadian currency tactile feature is a feature on current Canadian banknotes. Canadian banknotes are the Banknotes of Canada, denominated in Canadian dollars (CAD

Visually impaired and blind people have devised a number of techniques that allow them to complete daily activities using their remaining senses. These might include the following:

Most people, once they have been visually impaired for long enough, devise their own adaptive strategies in all areas of personal and professional management.

For corrective surgery of blindness, see acquired vision. Acquired vision is the phenomenon of a blind person gaining the ability to see usually as a result of medical treatment

Tools

Watch for the blind
Watch for the blind

Designers, both visually impaired and sighted, have developed a number of tools for use by blind people.

Mobility

Many people with serious visual impairments can travel independently assisted by tactile paving and/or using a white cane with a red tip - the international symbol of blindness. Tactile paving (also called truncated domes, detectable warnings, Tactile Ground Surface Indicators) is a system of textured ground surface A white cane is used by many people who are blind or Visually impaired, both as a mobility tool and as a courtesy to others The musical instrument is spelled Cymbal. A symbol is something --- such as an object, Picture, written word a sound a piece

A long cane is used to extend the user's range of touch sensation, swung in a low sweeping motion across the intended path of travel to detect obstacles. However, some visually impaired persons do not carry these kinds of canes, opting instead for the shorter, lighter identification (ID) cane. Still others require a support cane. The choice depends on the individual's vision, motivation, and other factors.

Each of these is painted white for maximum visibility, and to denote visual impairment on the part of the user. In addition to making rules about who can and cannot use a cane, some governments mandate the right-of-way be given to users of white canes or guide dogs. Traffic on Roads may consist of Pedestrians ridden or herded Animals Vehicles Streetcars and other Conveyances either singly "Guide Dogs" redirects here For the British charity see The Guide Dogs for the Blind Association Guide dogs are Assistance

A small number of people employ guide dogs. "Guide Dogs" redirects here For the British charity see The Guide Dogs for the Blind Association Guide dogs are Assistance The dogs can be trained to navigate various obstacles. The human half of the guide dog team does the directing, based upon skills acquired through previous mobility training. The handler might be likened to an aircraft's navigator, who must know how to get from one place to another, and the dog is the pilot, who gets them there safely.

Orientation and mobility specialists are professionals who are specifically trained to teach people with visual impairments how to travel safely, confidently, and independently in the home and the community.

Reading and magnification

Most visually impaired people who are not totally blind read print, either of a regular size or enlarged by magnification devices. Many also read large-print, which is easier for them to read without such devices. Large-print (also large-type or large-font) describes a type of book or other (paper online or otherwise published material in which the Typeface (or A variety of magnifying glasses, some handheld, and some on desktops, can make reading easier for them. magnifying glass (called a hand lens in laboratory contexts is a convex lens which is used to produce a magnified Image of an object

The rest read Braille (or the infrequently used Moon type), or rely on talking books and readers or reading machines. The Braille system is a method that is widely used by blind people to read and write The Moon System of Embossed Reading (commonly known as the Moon writing, Moon alphabet, Moon type or Moon code) is a Writing system A reading machine is a piece of Assistive Technology that allows blind people to access printed materials They use computers with special hardware such as scanners and refreshable Braille displays as well as software written specifically for the blind, such as optical character recognition applications and screen readers. A refreshable Braille display or Braille terminal is an electro-mechanical device for displaying Braille characters usually by means of raising dots through holes Optical character recognition, usually abbreviated to OCR, is the Mechanical or electronic translation of Images of handwritten typewritten A screen reader is a software application that attempts to identify and interpret what is being displayed on the screen (or more accurately sent to standard output

Some people access these materials through agencies for the blind, such as the National Library Service for the Blind and Physically Handicapped in the United States, the National Library for the Blind or the RNIB in the United Kingdom. The National Library Service for the Blind and Physically Handicapped is a free Library program of Braille and audio materials circulated to eligible borrowers in The National Library for the Blind ( NLB) was a public Library in the United Kingdom, founded 1882 which aimed to ensure that people with sight problems The Royal National Institute of Blind People ( RNIB) is a charity with its headquarters based in London, England, set up by Thomas Rhodes

Closed-circuit televisions, equipment that enlarges and contrasts textual items, are a more high-tech alternative to traditional magnification devices. Closed-circuit television ( CCTV) is the use of Video cameras to transmit a signal to a specific place limited set of monitors High tech is Technology that is at the cutting edge —the most advanced technology currently available So too are modern web browsers, which can increase the size of text on some web pages through browser controls or through user-controlled style sheets. A web browser is a software application which enables a user to display and interact with text images videos music games and other information typically located on a

Computers

Access technology such as screen readers and Screen magnifiers enable the blind to use mainstream computer applications. A screen reader is a software application that attempts to identify and interpret what is being displayed on the screen (or more accurately sent to standard output See also Magnifying glass A screen magnifier is software that interfaces with a computer's graphical output to present enlarged screen content Most legally blind people (70% of them across all ages, according to the Seattle Lighthouse for the Blind) do not use computers. The Lighthouse for the Blind Inc in Seattle is a Non-profit organization that provides employment support and training opportunities for individuals who are blind, Deaf-Blind Only a small fraction of this population, when compared to the sighted community, have Internet access. The Internet is a global system of interconnected Computer networks This bleak outlook is changing, however, as availability of assistive technology increases, accompanied by concerted efforts to ensure the accessibility of information technology to all potential users, including the blind. Later versions of Microsoft Windows include an Accessibility Wizard & Magnifier for those with partial vision, and Microsoft Narrator, a simple screen reader. Microsoft Windows is a series of Software Operating systems and Graphical user interfaces produced by Microsoft. Narrator is a light-duty Screen reader utility packaged with Microsoft Windows 2000, Windows XP and Windows Vista. Linux distributions (as Live CDs) for the blind include Oralux and Adriane Knoppix, the latter developed in part by Adriane Knopper who has a visual impairment. A Linux distribution (also called GNU/Linux by distributions such as Debian, Fedora, Ubuntu, Linux Mint, Mandriva and A live CD or live distro is a computer Operating system that is executed upon boot, without installation to a Hard disk drive. Oralux is an association whose objective is to foster digital accessibility using solutions based upon Free Software and open standards Knoppix, or KNOPPIX (nopɪks is a GNU/Linux Operating system based on Debian designed to be run directly from a CD / DVD Klaus Knopper (b 1968 in Ingelheim) is a German Electrical engineer and Free Software developer The Macintosh OS also comes with a built-in screen reader, called VoiceOver. VoiceOver is a feature built into Apple Inc 's Mac OS X operating system since version 10

The movement towards greater web accessibility is opening a far wider number of websites to adaptive technology, making the web a more inviting place for visually impaired surfers. Web accessibility refers to the practice of making Websites usable by people of all abilities and Disabilities. Adaptive technology is the name for products which help people who cannot use regular versions of products primarily people with physical disabilities such as limitations to vision hearing

Experimental approaches in sensory substitution are beginning to provide access to arbitrary live views from a camera. Sensory substitution means to transform the characteristics of one Sensory modality into stimuli of another sensory modality A camera is a device used to capture images either as still Photographs or as sequences of moving images ( Movies or Videos.

Other aids

People may use talking thermometers, enlarged or marked oven dials, talking watches, talking clocks, talking scales, talking calculators, talking compasses and other talking equipment. The thermometer is a device that measures Temperature or Temperature gradient using a variety of different principles it comes from the Greek roots A weighing scale (usually just "scale" in common usage except in Australian English where "scales" is more common is a Measuring instrument for A calculator is device for performing mathematical calculations distinguished from a Computer by having a limited problem solving ability and an interface optimized for interactive A compass, magnetic compass or mariner's compass is a navigational instrument for determining direction relative to the earth's Magnetic poles It consists

Sports

Blind and partially sighted people participate in sports such as swimming, snow skiing and athletics. Swimming is the movement by humans or animals through Water, usually without artificial assistance Snow skiing is a group of sports utilizing Skis as primary equipment Some sports have been invented or adapted for the blind such as goalball, cricket and golf. Goalball is a team Sport designed for blind athletes It was devised by Hanz Lorenzen (Austria and Sepp Reindle (Germany in 1946 Blind Cricket is a version of the Sport of Cricket adapted for blind and partially sighted players Blind golf is a version of the Sport of Golf adapted for blind and partially sighted players [18] The worldwide authority on sports for the blind is the International Blind Sports Federation (IBSA). The International Blind Sports Federation (IBSA, is a nonprofit organization founded in 1981 in Paris. [19] People with vision impairments have participated in the Paralympic Games since 1976. The Paralympic Games are a multi-sport event for athletes with physical and sensorial disabilities [20]

Blindness in animals

Statements that certain species of mammals are "born blind" refers to them being born with their eyes closed and their eyelids fused together; the eyes open later. Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands One example is the rabbit. Rabbits are small Mammals in the family Leporidae of the order Lagomorpha, found in several parts of the world

In humans the eyelids are fused for a while before birth, but open again before the normal birth time, but very premature babies are sometimes born with their eyes fused shut, and opening later.

Other animals such as the blind mole rat are truly blind and rely on other senses. Blind mole rats are one of many types of Rodents that are referred to as mole rats

Metaphorical uses

The word "blind" (adjective and verb) is often uses for various types of failing to notice something, for example in this page "For years I [= a gyrfalcon breeder] was impressed and blinded by the white color, but after I bred gyrs for a while I noticed that demand for darker falcons was very strong. The Gyrfalcon ˈdʒɜrˌfɔlkən or ˈdʒɜrˌfælkən ( Falco rusticolus) also spelled Gyr Falcon, sometimes Gerfalcon, is the largest ".

A "blind spot" is an area where someone cannot see, e. A blind spot, also known as a Scotoma, is an obscuration of the Visual field. g. where a car driver cannot see because parts of his car's bodywork are in the way.

See also

References

  1. ^ a b International Council of Ophthalmology. Accessibility is a general term used to describe the degree to which a product (e Amaurosis (Greek meaning darkening, dark, or obscure) is Vision loss or weakness that occurs without an apparent lesion affecting the Eye Blind musicians are Singers or Instrumentalists who are physically unable to see The practice of institutionalizing the blind in asylums has a history extending back over a thousand years but it was not until the 18th century that authorities created schools for The Braille system is a method that is widely used by blind people to read and write Color blindness, a Color vision deficiency is the inability to perceive differences between some of the Colors that others can distinguish Cortical blindness is the total or partial loss of vision in a normal-appearing Eye caused by damage to the visual area in the Brain 's Occipital cortex. Deafblindness is the condition of little or no useful sight and little or no useful hearing. Inattentional blindness, also known as perceptual blindness, is the phenomenon of not being able to see things that are actually there This is a partial list of human Eye diseases and disorders. The World Health Organization publishes a classification of known diseases and injuries called the Nyctalopia (Greek for " night blindness " is a condition making it difficult or impossible to see in relatively low light A scotoma ( Greek: darkness; plural "scotomas" or " scotomata " is an area or island of loss or impairment of Visual acuity Snow blindness (Niphablepsia is a painful condition typically a Keratitis, caused by exposure of unprotected Eyes to the Ultraviolet (UV rays in bright The slate and stylus are tools used by blind persons to write text that they can read without assistance Stereoblindness (also stereo blindness) is the inability to see in 3D using Stereo vision, resulting in inability to perceive stereoscopic depth Web accessibility refers to the practice of making Websites usable by people of all abilities and Disabilities. "International Standards: Visual Standards — Aspects and Ranges of Vision Loss with Emphasis on Population Surveys." April 2002.
  2. ^ Belote, Larry. "Low Vision Education and Training: Defining the Boundaries of Low Vision Patients." A Personal Guide to the VA Visual Impairment Services Program. Retrieved March 31, 2006.
  3. ^ Living with Low Vision - American Foundation for the Blind
  4. ^ http://www3.who.int/icd/currentversion/fr-icd.htm
  5. ^ WHO | Magnitude and causes of visual impairment
  6. ^ a b Koestler, F. A. , (1976). The unseen minority: a social history of blindness in the United States. New York: David McKay.
  7. ^ Corn, AL; Spungin, SJ. "Free and Appropriate Public Education and the Personnel Crisis for Students with Visual Impairments and Blindness." Center on Personnel Studies in Special Education. April 2003.
  8. ^ http://www.ssa.gov/history/pdf/80chap12.pdf
  9. ^ Social Security Act. "Sec. 1614. Meaning of terms." Retrieved February 17, 2006.
  10. ^ Al-Merjan JI, Pandova MG, Al-Ghanim M, Al-Wayel A, Al-Mutairi S. "Registered blindness and low vision in Kuwait. " Ophthalmic Epidemiol. 2005 Aug;12(4):251-7. PMID 16033746.
  11. ^ a b Kirchner, C. , Stephen, G. & Chandu, F. (1987). "Estimated 1987 prevalence of non-institutionalized 'severe visual impairment' by age base on 1977 estimated rates: U. S. ", 1987. AER Yearbook.
  12. ^ American Foundation for the Blind. "Statistics and Sources for Professionals." Retrieved April 1, 2006.
  13. ^ World Health Organization (Web). World Health Organization (2006). Retrieved on December 16, 2006.
  14. ^ Bunce C, Wormald R. "Leading Causes of Certification for Blindness and Partial Sight in England & Wales." BMC Public Health. 2006 March 8;6(1):58 [Epub ahead of print]. PMID 16524463.
  15. ^ Methanol (Web). Symptoms of Methanol Poisoning. Canada Safety Council (2005). Retrieved on March 27, 2007.
  16. ^ http://content.nejm.org/cgi/content/full/NEJMoa0802268
  17. ^ [1]
  18. ^ Blind Sports Victoria. Retrieved on 2008-03-04. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 51 - Nero, later to become Roman Emperor, is given the title Princeps iuventutis (head of the youth
  19. ^ IBSA General Assembly Elects New Leadership. The Paralympian. International Paralympic Committee (April 2001). Retrieved on 2008-03-04. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 51 - Nero, later to become Roman Emperor, is given the title Princeps iuventutis (head of the youth
  20. ^ The history of people with disabilities in Australia - 100 years. Disability Services Australia. Retrieved on 2008-03-04. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 51 - Nero, later to become Roman Emperor, is given the title Princeps iuventutis (head of the youth

External links

Dictionary

blindness

-noun

  1. The condition of being blind; unable to see.
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