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| لماذا يلبس الأعمى نظارة سوداء وهو لا يرى ؟ | |
| | كاتب الموضوع | رسالة |
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ابراهيم الشنطي Admin
عدد المساهمات : 75783 تاريخ التسجيل : 28/01/2013 العمر : 78 الموقع : الاردن
| موضوع: لماذا يلبس الأعمى نظارة سوداء وهو لا يرى ؟ الجمعة 13 يناير 2017, 8:28 pm | |
| لماذا يلبس الأعمى نظارة سوداء وهو لا يرى ؟ أحد أكثر الأسئلة شيوعًا على مر السنين. فمجرد أن ترى شخص مكفوف يسير أمامك حتى تستغرب من ارتدائه نظارة سوداء على الرغم من أنه فاقدٌ للبصر ولا يرى! فما الهدف من ارتداء النظارة ؟ في بادئ الأمر يجب أن تُدرك أن الشخص الأعمى ليس بشرطٍ أنه فاقدٌ للبصر تمامًا، فالكثير ممن يندرجون تحت هذا الصنف من الناس قادرين على استشعار رؤية بسيطة وخفيفة جدًا لكن ليس بقدرة الشخص الطبيعي على الإبصار. وبسبب طبيعة أعينهم التي غالبًا ما تكون حساسة للضوء، فإن أفضل وسيلة هي ارتداء نظارة سوداء لحماية أعينهم من الأشعة الساطعة حيث أن اللون الداكن يعكس ويحجب تلك اللإضاءة. كما أن الكثير من النظارات السوداء تعمل على تصفية الأشعة الواصلة للعين وتُرشحها من الأشعة فوق البنفسجية والضوء الساطع اللذيْن يُشكلان ضررًا كبيرًا على الأعين الحساسة. وقد تتساءل ما الخطر من وصول الأشعة فوق البنفسجية لعين الأعمى طالما أنها لا تؤدي مهمتها الأساسية وهي الإبصار. من هنا كان لا بد لك أن تعلم أن خطر الأشعة فوق البنفسجية لا يتوقف فقط على تهديد البصر، إنما أيضًا له توابع خطيرة أخرى كإلتهاب القرنية (العمى الثلجي) أو التهاب الملتحمة (التهاب الملتحمة الضوئي). وينتج هذان النوعان من التهابات العين عن حروق الشمس بفعل الأشعة الضارة. وفي بعض الحالات شديدة الخطورة، يتطوَّر الأمر إلى سرطان في العين خاصةً للأعين الحساسة. والمكفوفين أكثر عرضة من غيرهم للإصابة بأمراض العين المختلفة بفعل الضوء الساطع والإشعاع. سببٌ آخر لارتداء الأعمى لنظارة سوداء هو حماية العين من المخاطر التي قد يتعرض لها خلال سيره في الطريق كالفروع المتدلية والأشياء الصغيرة المتطايرة في الهواء أو الأبواب المفتوحة. كما أن النظارات كالعصا البيضاء تمامًا تدل على أن الشخص أعمى. فبمجرد مشاهدته من بعيد خاصةً في الأماكن المُغلقة، يُمكنك التمييز بأنه يُعاني من مشكلة في عينيه للتعامل معه بالطريقة الصحيحة. بعض المكفوفين يرتدون نظارات سوداء منعًا للحرج. فالنظر والتحدث إلى شخصٍ يرتدي نظارة مريح أكثر من النظر إلى شخصٍ تتحرك حدقات عينيه بشكلٍ عشوائي، أو مبيضة، أو ذات نظرات غريبة. فعندما يرتدي الأعمى نظارات غامقة يحمي نفسه من الأحكام التي قد يطلقها الشخص المقابل، والذي اعتاد على الحكم على الآخرين من خلال تواصل العينين. Why do blind people wear glasses when they can't see? Arie Anna Farnam, legally blind mother, author and urban homesteader - my spelling is suspect Dear reader,
I am going to try very hard to be polite here. It isn't easy because this question makes my blood boil. I am often harassed by people who take exception to the combination of my white cane, my glasses and the printed book that I am reading on the train. But since you asked, I will try to clear this up for once and for all. Read this next sentence very carefully please.
Most "blind people" can see some.
There are people who are totally blind. Some of them where glasses. Some reasons might be 1. to cover disfigured eyes and thus gain a bit in social acceptance, 2. to protect their face from branches and other obstacles and 3. to let other people know they can't see (again in order to avoid social problems and as a traffic safety measure).
However, 90 percent of legally blind people can see something, even if just light. Those who can see only light are often light-sensitive and bright light can cause pain. If they can't see much beyond light, they will rarely have a warning when bright light is coming. So, dark glasses are a real necessity.
And then there are the rest of us, i.e. most people who are legally blind who can actually see some but not much. We often wear glasses in order to improve our vision. There are legally blind people with an extremely narrow field of vision (sometimes called tunnel vision) who can otherwise see pretty well but only in a small area. A person with that kind of vision problem may or may not need glasses.
Then again many legally blind people are simply extremely nearsighted. This is my specific vision impairment. I am so nearsighted that my eyes focus about an inch from the lens. Very heavy glasses push this point out to about two inches, which may not sound like a big improvement but it significantly improves what I can see at ten feet. Everything at ten feet is still really blurry either way but without glasses it is just a massive blur with no distinction. With glasses there are lumpy fuzzy large objects. So, glasses make a big difference. Contact lenses are actually more effective in my case (explaining why would take a very long scientific explanation of optics and the distances between lenses). But the extraordinarily thick contact lenses I wear tend to damage your cornea, so I can't wear them very often. Thus the glasses.
And just to complete the explanation (although I know you aren't the irate train conductor from yesterday who didn't believe that I'm legally blind because I was reading The Little House in the Big Woods in print to my daughter on the train with my white cane propped on my knee) I can see reasonably well at two inches. That is why I was reading the book so close. (No, please do not mash the book into my face and claim that you are helping me get it closer as so many people have or I will stop being polite.) I cannot, however, see the gray-on-gray steps on the train and if I don't use a white cane (or a good memory and some echolocation) I might trip. I also use the white cane to tell you why my eyes are a bit squinty and why they move erratically. The fact that I have a white cane will tend to make you realize that I probably can't see well. Otherwise, most people immediately assume I have a mental or developmental disability. Given the choice, I prefer the nasty social things most people do to blind people over the nastier social things most people do to people with developmental disabilities. So, even though I can usually get around pretty well (even over those gray-on-gray steps) with echolocation and memory, I have started carrying a white can in order to avoid endless explanations and ostracism.
Ironically, the other most common reason I am harassed in public over my vision impairment is when I wear contact lenses instead of glasses. I can't count the times a complete stranger has lectured at me about how I need to go to the eye doctor and get glasses, when they see how close I'm holding my book. I have heard many people insist that glasses can always "cure" any nearsightedness. I have tried to explain the principles of optics to them and the fact that nearsightedness can only be corrected so far and that, in any case, there are these wonderful new things that came out... oh... about fifty years ago called "contact lenses" and I'm wearing a state-of-the-art example that works far better than any glasses.
The point of all this and the answer that you didn't ask for is this. Please, dear reader, don't bug people about their glasses or lack there of or their cane or lack there of or their wheelchair or their hearing aid or any such thing or lack there of. It is their device and their responsibility. If they are your friend (or on Quora) and you're curious, they'll probably be happy to explain, if you ask politely. The fact that someone has a disability card that says they are blind and yet they don't have a white cane and they either do or don't wear glasses does not mean that they have forged the disability card. It means they have good orientation and mobility skills, some ability with echolocation and rhino skin when it comes to the social world. Doctors are in charge of diagnosing vision problems and helping people determine what sorts of glasses or other optical aids they need. It is not your job to attempt to give such advice on the subway or in the workplace or at school or anywhere, unless you're medical vision specialist (in which case I hope you're laughing by now). |
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عدد المساهمات : 75783 تاريخ التسجيل : 28/01/2013 العمر : 78 الموقع : الاردن
| موضوع: رد: لماذا يلبس الأعمى نظارة سوداء وهو لا يرى ؟ الجمعة 13 يناير 2017, 8:35 pm | |
| هل يحلم المكفوفين؟ وماذا يشاهد الأعمى في أحلامه؟ لحلم ليس حكرًا على الأشخاص المبصرين فقط، فكل شخص يحلم اعتمادًا على ما عايشه في الحقيقة. لكن السؤال الذي يدور في بال الجميع الآن، هو كيف للأعمى أن يحلم؟ وهل أحلامه تُشبه أحلام المبصرين؟ وماذا يرى فيها؟ بالتأكيد، فإن الأشخاص المكفوفين يحلمون كسائر البشر، لكن تختلف أحلام الشخص الأعمى عن الآخرين بسبب اختلاف طبيعة ما يُعايشه في الحقيقة. وهُنا يُمكن تصنيف المكفوفين إلى قسمين للحكم على نوعية الأحلام: * أعمى منذ الولادةهذا النوع يحلم كالآخرين تمامًا لكن لكنه لا يرى صورًا في الحلم، وإنما تعتمد أحلامه على حواسه الأخرى كالشم والرائحة والطعم. فيُمكنه أن يشعر بطعم الأشياء في منامه أو رائحتها، لكنه لا يراها مُطلقًا. * أعمى بعد إبصارأما من فقد حاسة البصر بعد فترة من الإبصار لأي سببٍ كان سواء حادث أو مرض أو شيءٍ آخر، فيُمكنه أن يُشاهد صورًا اعتمادًا على ما عايشه خلال فترة إبصاره. فتجربته البصرية في الحلم محدودة بأشكال وألوان معينة، لكن الوضوح في هذه الأحلم يتلاشى مع الزمن. تجربة دنماركية..وكان باحثون دنماركيون قد حاولو التوصل إلى حقيقة أحلام المكفوفين عبر تجربة تطوَّع خلالها 50 شخصًا بالغًا. 11 منهم مكفوفين منذ الولادة، 14 منهم فقدوا البصر في مرحلة عمرية ما بعد سن العام الواحد، و25 شخصًا مُبصرين. التجربة اشترطت على المتطوعين بأن يقوموا بملء استبيان عبر الحاسوب بعد استيقاظهم مباشرةً من النوم إن صادفوا حلمًا خلال نومهم. بالطبع فإن المكفوفين استعملوا برامج تحويل الكلام إلى نص عبر الحاسوب. هذه التجربة بيَّنت أن المكفوفين يحلمون لكن ليس بذات الطريقة التي يحلم بها المُبصِر. فأحلام المكفوفين هي مزيج من المعلومات الحسية التي يُدركها. حوالي 18% من المشاركين المكفوفين أفادوا بأنهم تذوقوا طعمًا في حلم واحد على الأقل. و30% منهم أفادوا أنهم شمّوا رائحة واحدة على الأقل في الأحلام. وعلى الرغم من اختلاف الطبيعة الحسية بين أحلام المكفوفين والمبصرين، إلا أنها لا تختلف في شعور الحالم بها وتُعطي نفس شعور المبصر خلال حلمه. دراسات أخرى أفادت أن الأعمى يُمكن أن يتخيَّل أشكالًا في أحلامه، تمامًا كما يتخيل الطفل وحوشًا سمع بها من القصص الخيالية في أحلامه. لذلك، فالأعمى قد يتخيل أن الإنسان شكله هكذا، واللون الأحمر هو هكذا، والطير هكذا. فكما رسم الصورة في خياله يحلم بها. لأن الحلم هو انعكاس تفكير العقل الباطن بالأشياء المتكررة الظهور أو الموجودة في صورة الخيال. |
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عدد المساهمات : 75783 تاريخ التسجيل : 28/01/2013 العمر : 78 الموقع : الاردن
| موضوع: رد: لماذا يلبس الأعمى نظارة سوداء وهو لا يرى ؟ الجمعة 13 يناير 2017, 8:36 pm | |
| If a person is born blind, what do they see in their dreams? Janice Strange, I was blind for 13 years. Not only was I blind but I worked with the blind as well. Dreaming is more than just seeing. People who are born blind experience dreams the same way they experience reality. They relive things that happened and imagine things that could happen. However, sight is not part of the dream. They do experience, sound, touch and feelings in the dreams.
Those who go blind later, will experience some sort of sight while they are dreaming. From my own personal experience, I thought it was quite funny.
At first, I could see just fine in my dreams, However, over time, I began dreaming I was blind. For example, I would dream I was walking through the mall and asked them to read signs to me and ask directions. When I woke up, I found this funny because it was my dream afterall and therefore, I had to know the answer.
Yuan Gao, Engineer Written Sep 28, 2015The best person to answer this question is someone who has been blind since birth. One such individual is Tommy Edison, who has an awesome youtube channel where he explains all sorts of things from the perspective of a blind person, including answering the question: how do blind people dream? You should check it out: TommyEdisonXPPeter Clark, growth @ adroll Written Jun 10, 2010 - اقتباس :
- Three careful sleep laboratory studies (Amadeo & Gomez, 1966; Berger, Olley, & Oswald, 1962; Kerr, Foulkes, & Schmidt, 1982) and at least one rigorous study of home dream reports (Hurovitz, Dunn, Domhoff, & Fiss, 1999) have shown that
- اقتباس :
- congenitally blind dreamers and those who became blind in infancy do not have visual imagery in their dreams
- اقتباس :
- , whereas those blinded in adolescence or young adulthood often retain visual mental imagery in their waking life and in their dreams. These controlled experiments confirm what has been reported in a number of earlier self-report studies reviewed by Kirtley (1975), who concluded on the basis of his extensive appraisal that
- اقتباس :
- individuals blinded before the age of about 5 report no visual imagery in dreams as adults, whereas those blinded after about the age of 7 are likely to retain visual imagery in dreaming
Lui Batongbakal, Trivia Blogger; Founder and Editor-in-Chief of FilipiKnow.net Updated Jan 19, 2016As a trivia blogger and someone who personally knows blind people, I've explored this topic already and written an article about it. Here goes: Both the blind people and those who can see have the capability to form memories; hence, all people can dream regardless of their vision. The difference lies in the type of dream we experience. In 2014, a group of Danish researchers found that what blind people dream about depends on whether they were born blind or they have late-onset blindness (meaning they lost their vision after their first birthday or beyond). Those who once had a normal eyesight usually have dreams containing remnants of their past–people, places, and events that were stored in their memories before they went blind. For those with congenital blindness, however, the absence of visual elements is offset by activation of their other senses. In fact, in the same study, the blind participants reported more incidents of hearing, touching, smelling, and tasting in their dreams compared to the control group.People who were born blind may not see anything in their dreams, but theirs are as emotional as ours–sometimes even more terrifying. In the study, the blind had more nightmares (25 percent, compared with just 6 percent of the controls and 7 percent of the later-onset blind group). These nightmares were real threats in their waking lives–like falling into manholes and getting hit by a car–and are believed to be an evolutionary mechanism to help blind people “rehearse the threat perception and the avoidance of coping with the threat.”Mario BergerWritten Feb 20, 2013I have found another interesting research on this topic that came up with an interesting conclusion. You can read the whole thing here: http://www.uv.es/revispsi/articu...I'll copy/paste just relevant parts of it. Quoting: - اقتباس :
- Dreams with visual content are expressions of visual imagery.
Therefore if dreams with visual content could be demonstrated in congenitally blind persons, this would imply that visual imagery is possible in subjects who have been prevented from having visual experiences. Furthermore, this would allow one to infer that visual imagery does not depend on specific visual perception, but can emerge from activation of visual cortex by nonvisual inputs (Lopes da Silva, 2003).
It is open to discussion whether congenitally blind subjects have dreams with visual imagery content, and if they do, whether this ability represents images capable of being represented graphically. Since for sighted subjects the dreaming experience is associated withVisual Imagery and Visual Perception 181 visual activity, it used to be widely thought that blind persons do not dream. This was strongly refuted by several authors and it is nowadays accepted that the dreams of the blind are vivid and self-engaging (Deutsch, 1928; Jastrow, 1900; Kerr, 2000). Furthermore, it is currently accepted that the congenitally blind, or those who lose their sight before the age of 5 or 7, have dreams without visual content (Kerr, 2000). Jastrow’s studies on children’s dreams found visual imagery only in those whose blindness occurred after 5-7 years of age (Jastrow, 1900), a period associated with the inclusion of visual activity in dreams, which coincides with the beginning of autonomous dreaming (Foulkes, 1982). Some authors also report that subjects who are born blind report dreams which do not include any description of scenes or landscapes but contain mostly sounds, touch sensations or emotional experiences (Holzinger, 2000; Hurovitz, Dunn, Domhoff & Fiss, 1999; Lavie, 1996). Laboratory dream data obtained for 10 blind subjects showed that blind and normal dreams were identical, except for 2 congenitally blind subjects whose dreams did not have visual components (Kerr, Foulkes & Schmidt, 1982). This knowledge may, however, be questioned. Using objective measurements, to access visual imagery in blind subjects, we evaluate visual content in dreams and its relation with EEG’s spectral rhythms (Bértolo, Paiva, Pessoa, Mestre, Marques & Santos, 2003).
Our results Taking the above information into consideration, we analysed EEG alpha power in congenitally blind subjects, as a possible indicator of the visual content of their dreams (Bértolo et al., 2003), and evaluated the ability of congenitally blind to graphically represent the dream-evoked images. We tested 10 congenitally blind and 9 sighted subjects, during two consecutive nights of home PSG (polysomnographic) recordings, with serial awakenings for dream recall. Content analysis was performed on the dream reports using the Hall & Van de Castle definitions to code the different activities (Domhoff, 1996). The dream reports of the blind subjects were vivid with tactile, auditory and kinaesthetic references, but also with visual content. Neither the Global Activity Index (GAI) nor the Visual Activity Index (VAI) showed any difference between the two groups (Bértolo et al., 2003). When comparing the Content variables with the EEG spectral components, we observed in both groups (blind and sighted) a negative correlation between the VAI and the alpha power: where the visual activation index increased, the alpha power decreased (Bértolo et al., 2003). This negative correlation between alpha and the VAI was also found in a previous study with a smaller sample (Bértolo & Paiva, 1999). Two different tasks were used to evaluate graphical representations; in both of them sighted subjects performed the tasks with their eyes closed. First the subjects were asked to make a drawing of one their dream scenes. A qualitative analysis of these representations was performed with respect to complexity and content. In the second task the subjects were asked to draw “ a182 H. Bértolo human figure the best you can”. Two different scales were used to evaluate this task. Quoc Vu’s Test (Cambier & Quoc Vu, 1985) and The Goodenough scale (Goodenough, 1928). All the subjects performed the first task of graphical representation, the drawing of a dream scene (Fig.1). Blind subjects were able to represent graphically the oneiric scenes they previously described orally. No statistical differences were found between the groups (Bértolo et al., 2003).
With respect to the “Drawing of the Human Figure” (Fig.2) the only statistical difference between the groups for Quoc Vu’s Test was related to the vertical occupation of the drawing: the blind tended to draw on the left side of the sheet of paper. On Goodenough’s scale, the human figure was recognisable in both groups, and of the 51 items characterising the drawing only one was statistically different: ears are more often represented by blind than by sighted subjects (Bértolo et al., 2003). In conclusion, the congenitally blind are not only able to describe what may be the visual content of their dreams verbally, but they can provide, through drawing, a graphical representation of such content, and a significant negative correlation between the Visual Content of the dreams and the alpha power was found in both groups.
According to these results, the congenitally blind, who have never experienced sight, are able to visualise. This is in line with previously mentioned studies related to the capacity for visual imagery in individuals who are born blind, showing that they present only slight or no differences when compared with normal sighted subjects.
Behind such controversy lies the fact that experience is considered essential both for visual imagery and for visualisation. Visualisation without previous experience, as is the case for congenitally blind, would indicate the existence of visual imagery independent of visual perception. This implies that the born-blind subjects are capable of using other sensory modalities to integrate these inputs via the visual system to produce concepts capable of graphical representation.
The discussion around the term “visual imagery” - seeing with the “mind’s eye” - is far from being resolved. Nevertheless the use of the term in our paper was carefully applied. We totally agree that sometimes blind subjects use terms as “seeing” in their daily lives metaphorically. But this does not imply that they are unable to produce mental visual images. In informal talks blind subjects told us that when they sign their names they don’t use a memorised set of movements, instead they “visualise” their signature and reproduce it. One of the volunteers told us that during dream he experienced visual images but whenever he report that to anyone he was told he didn’t see things he just felt them; and so he was very reluctant to share those experiences with others.
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