Blindness: Causes and Use of Technology to Teach Blind Students - Essay Example

Blindness: Causes and Use of Technology to Teach Blind Introduction Blindness is the condition of being unable to see. It is the severe visual decline in one’s eyes. Lack of sight makes people not to be able to differentiate between light and darkness, and even eyeglasses and contact lenses are may not help a blind person to see. Blindness is the inability to see even when one wears glasses. Therefore, if someone cannot see without the aid of glasses he or she is not considered to be blind in the sense of the definition of blindness. There are several causes of blindness which depend on the socioeconomic conditions affecting people. Some of the causes include infections, injuries, lack of glasses, trauma, etc. Blind students are also taught using various technologies, including Braille and assistive computer technology. These technologies enable students to read and listen to lecture notes, presentations, course materials and other reading materials. Causes of Blindness Causes of blindness depend on the socioeconomic conditions to which a person is exposed. They include causes that affect the eye directly and those that affect visual processing centres like the brain. In developed economies, the primary causes of blindness include macular degeneration, traumatic injuries and ocular diabetes complications. In developing and underdeveloped nations blindness is caused primarily by infections, glaucoma, lack of glasses, injury, and cataracts. Some of the infections that lead to blindness in underdeveloped countries include onchocerciasis (river blindness), leprosy and trachoma. The herpes simplex is the most common cause of blindness in developed countries. There are also other causes of blindness such as retinopathy, deficiency of vitamin A, diseases affective the retina or optic nerve e.g. stroke, inflammation, eye malignancies, abnormalities of the congenital, hereditary eye diseases, and chemical poisoning. According to Bourne et al (2013), cataracts and macular degeneration are the leading causes of blindness. Cataracts affect people from developing and underdeveloped world while macular degeneration mainly affects people from developed countries. Amblyopia Blindness can also be caused by amblyopia, or the lazy eye. This refers to the condition in which a child is born with poorer vision in one eye than the other (NIH Medline Plus, 2015). Untreated amblyopia leads to vision loss and blindness. As the child grows, the brain ignores images from the affected eye, leading to loss of vision in that eye as the child enters teenage stage of life. The condition starts when one of the child’s eyes develops a better focus than the other, causing the brain to be confronted with blurred and clear images. With time, the brain learns to ignore the blurred image and the bad eye ends up losing sight completely. Oscular misalignment as a cause of blindness limits the eyes from focusing on the object together, causing double vision (NIH Medline Plus, 2015). As a result, the brain chooses the normal eye over the deviated eye, and ignores the images of the deviated eye. This eventually leads to loss of sight by the misaligned eye. Cataracts Cataracts refer to the clouding that occurs on the lenses of human eyes. They affect vision, mainly in older people and it is the leading cause of blindness. Although cataracts affect developing world more than the developed world, they occur in all parts of the world. According to MedlinePlus (2015), there are about 22 million Americans with cataracts. Cataracts are associated with the following symptoms: blurry vision, glare, inability to see properly at night, double vision, and faded colors. They can be treated by wearing new glasses, anti-glare sunglasses, magnifier lenses, brighter lighting and surgery. Surgery involves replacing the cloudy layer of the eye with an artificial lens. Cataracts may also be delayed by wearing a hat and some sunglasses to prevent ultra-violet sunlight. Glaucoma Glaucoma is a condition that affects the optic nerve of the eye, and can cause blindness. It occurs as a result of the rise of fluid pressure in the eye, causing damage to the optic nerve. It is difficult to determine whether a person has glaucoma because symptoms cannot be detected at first until a comprehensive eye check is done. MedlinePlus Magazine (2015) suggests that there are 2.3 million cases of Glaucoma in Americans. Prescription eye drops or surgery can be used to treat glaucoma. However, the disease is not curable. Diagnosis or treatment only serves to control the condition before the onset of blindness. Preventing the optic nerve is also an important way of controlling glaucoma. Macular Degeneration This is an age-related condition that mainly affects old people of 60 years and above. It affects eyesight by destroying the sharp, central vision that enables the eye to see objects vividly (American Macular Degeneration Foundation, 2011). This prevents the ability of affected person to read, watch television, drive or perform essential daily routine activities. Macula is the part of the eye that enables one to see objects clearly. Macula degeneration deadens the cells in the macula. It occurs so slowly that it becomes difficult for the affected individual to notice vision changes. It may cause vision impairment to both eyes. Macular degeneration also occurs in two ways – dry and wet macular degeneration. Wet degeneration takes place as a result of growth of abnormal blood vessels behind the retina of the macula. Dry degeneration of the macula takes place due to slow breakdown of light-sensitive macula cells. Diabetic Retinopathy Diabetic retinopathy is also a common cause of vision loss. It occurs as a result of diabetes. This condition causes problems in the retina, and affects vision mainly in adults aged eighteen years and above (NIH Medline Plus, 2015). This condition may be treated using surgery, and patients should conduct eye checks regularly. Technologies used to teach people with visual disabilities People with blindness are taught using various technologies. Two of the most common categories of technologies used to teach blind people are Braille and assistive computer technology. These technologies are adaptive devices intended to increase participation and achievement of blind people at the classroom. Assistive Computer Technology Generally, assistive technology (AT) is used by visually impaired students to access general curriculum accessed by other students and perform better academically. Assistive computer technology consists of a combination of software and hardware used by students to increase their access of curriculum and learning materials in school. Such computers have in-built accessibility options for blind people, including arm support, track pad, tracker, touch screen, voice recognition software, screen reader, and word prediction expansion (Robitaille, 2010). Special screen magnification software such as Lunar and Supernova software can be used to adjust the screen display of the computer to meet the needs of each individual. Assistive screen reader software also keeps track of events on the screen and alerts the user about specific issues. For completely blind individuals, assistive computer technology is enhanced through specialized speech screen reading software (Robitaille, 2010). The computer software synthesizes speech to read screen contents and texts for the blind students to access learning information and curriculum. Learning software using speech allows students to interact with their surrounding environment in order to experience effective learning. Braille Braille is a writing system that allows blind learners to write and read information with an embossed paper. A slate or stylus is used to write Braille or type it on a Braille writer. A computer can also be used to write Braille and print it with a Braille embosser (Castellano & Kosman, 1997). The Braille characters include small rectangular-shaped cells with small bumps known as raised dots. Blind people differentiate one character from another by noting the number and arrangement of the dots. English Braille is categorized into three coding categories. Grade 1 includes a letter-by-letter transcription used for basic literacy purposes; Grade 2 adds contractions and abbreviations to the basic literacy; and grade 3 includes personal short hands. Braille typewriter has six dots used to write. The dots are created at the back of the brailler using a mirror image. eBrailler has also been devised to write electronically. When writing on Braille, an error is corrected by overwriting using all the six dots of the Braille typewriter. The Braille transcribes 25 letters of the alphabet from A to Z, skipping W (Castellano & Kosman, 1997). Braille can also be produced using a Braille translation software in a computer. It enables Braille to be used in common languages of the world and to handle technical areas such as Mathematics and Music. When reading the Braille, a blind person should have the skill to create even and smooth pressures to run his or her fingers along the words. Conclusion Blindness is a common disability affecting learners. It is caused by conditions such as macular degeneration, diabetic Retinopathy, cataracts, glaucoma and Amblyopia. Diabetic Retinopathy occurs as a result of diabetes; macular degeneration destroys the sharp, central vision that enables the eye to see objects vividly; glaucoma affects the optic nerve of the eye; cataracts form clouding that occurs on the lenses of human eyes; and amblyopia occurs when a child is born with poorer vision in one eye than the other. Technologies used to teach blind students include Braille and assistive computer technology. Assistive computer technology consists of a combination of software and hardware used by students to increase their access of curriculum and learning materials in school while Brailler is a machine used by blind people to write and read information using dots that represent 25 letters of the alphabet. References List American Macular Degeneration Foundation. (2011). A brighter tomorrow: Promising research on macular degeneration. Northampton, MA: American Macular Degeneration Foundation. Bourne, R.R.A., Stevens, G.A., White, R.A., Smith, J.L., Flaxman, S.R., Price, H., Jonas, J.B., Keefft, J., Leashert, J., Naidoot, K., Pesudovst, K., Resnikoff t, S., Taylort, H.R. (2013). Causes of vision loss worldwide, 1990–2010: a systematic analysis. The Lancet, 1, December Issue, 339-349. Castellano, C., & Kosman, D. (1997). The bridge to braille: Reading and school success for the young blind child. Baltimore: National Organization of Parents of Blind Children. NIH Medline Plus (2015). Leading Causes of Blindness. MedlinePlus Magazine, Accessed April 29, 2014 from http://www.nlm.nih.gov/medlineplus/magazine/issues/summer08/articles/summer08pg14-15.html. Robitaille, S. (2010). The illustrated guide to assistive technology and devices: Tools and gadgets for living independently. New York: Demos Medical Pub. Read More