首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
医学
Famed singer Steve Wonder can’ t see his fans dancing at his concerts. He can’ t see the hands of his audience as they applaud w
Famed singer Steve Wonder can’ t see his fans dancing at his concerts. He can’ t see the hands of his audience as they applaud w
admin
2013-11-30
60
问题
Famed singer Steve Wonder can’ t see his fans dancing at his concerts. He can’ t see the hands of his audience as they applaud wildly at the end of his Superstition.
Blind from birth, Wonder has waited his whole life for a chance to see. Recently, Wonder visited Mark Humayan, a vision specialist. He thought that a new device currently being studied by Humayan might offer him that chance.
The device, a retinal prosthesis, is a tiny computer chip implanted inside a patient’ s eye. The chip sends images to the brain and allows some sightless people to see shapes and colors. Wonder hoped the retinal prosthesis might work for him. "I’ ve always said that if ever there’ s possibility of my seeing," said Wonder, "then I would take the challenge. "
Unfortunately for Wonder, that challenge will have to wait. Humayan explained that the device isn’ t ready for people who have been blind since birth. Their brains may not be able to handle signals from a retinal prosthesis because their brains have never handled signals from a healthy eye.
However the retinal prosthesis and other devices show great promise in helping many other sightless people who once had vision see again. Perhaps one day soon, some formerly sightless people may be in Wonder’ s audience looking up—and seeing him—for the very first time.
Wonder’ s willingness to take part in retinal prosthesis studies and the results of those studies are giving new hope to people who thought they would be blind for the rest of their lives. More than one million people in the United States are considered legally blind, meaning that their eyesight is severely impaired. Another one million are totally blind.
Two types of specialized cells in the retina—rods and cones—are critical for proper vision. Light enters the eye and fails on the rods and cones in the retina. Those cells convert the light to electrical signals, which travel through the optic nerve to the brain. The brain interprets those signals as visual images. Rods detect light at low levels of illumination. For instance, rods allow you to see faint shadows in dim moonlight. Cones, on the other hand, are most sensitive to color. Some diseases can damage cells in the retina. For instance, macular degeneration causes blindness and other vision problems in 700,000 people in the United States each year. The condition is caused by a lack of adequate blood supply to the central part of the retina. Without blood, the rods, cones, and other cells in the retina die.
Devices such as the retinal prosthesis won’ t prevent or cure our eye diseases, but they may help patients who have eye disorders regain some of their vision. Different forms of retinal prosthesis are currently being developed. On one type, a tiny computer chip is embedded in the eye. The chip has a grid of about 2,500 light-sensing elements called pixels.
Light entering the eye strikes the pixels, which convert the light into electrical signals. The pixels then send the electrical signals to nerve cells behind the retina. Those cells send signals via the optic nerve to the brain for interpretation.
Many people who have had a retinal prosthesis implanted say they can see shapes, colors, and movements that they couldn’ t see before. "It was great," said Harold Churchey, who received his retinal prosthesis 15 years after he became totally blind. "To see light after so long—it was just wonderful. It was just like switching a light on. "
Why does macular degeneration cause blindness and other vision problems?
选项
A、Macular degeneration causes improper interpretation by the brain.
B、Macular degeneration makes the retina less sensitive to the light.
C、Macular degeneration changes the functions of rods and cones.
D、Macular degeneration causes inadequate supply of blood in the retina.
答案
D
解析
文章第七段倒数第二句指出“The condition is caused by…of the retina”,即这种情况是由于视网膜中部缺血导致,选项D正确。
转载请注明原文地址:https://kaotiyun.com/show/MtU3777K
本试题收录于:
医学博士外语题库考研分类
0
医学博士外语
考研
相关试题推荐
Severalclassesofbittercitruscompoundhavelookedpromisingasanticanceragentsinlaboratorytests.Anewstudyindicates
Severalclassesofbittercitruscompoundhavelookedpromisingasanticanceragentsinlaboratorytests.Anewstudyindicates
Cultureshockmightbecalledanoccupationaldiseaseofpeoplewhohavebeensuddenlytransplantedabroad.Likemostailments,
A、Themathcourseisratherdifficult.B、Thewomanaskedawrongperson.C、Thewomanshouldtakeabasicmathcourse.D、Theman
Politiciansoftenuseemotionalratherthanrationalargumentstowinthesupportfortheiractionsandideas.
A、AbriefhistoryofBritishpubs.B、Beer—theBritishnationaldrink.C、VariousattemptsmadetocurbdrinkinginBritain.D、The
A、Becausetheydreadthattheywillhavetoseeapsychiatrist.B、Becausetheythinkthatanxietyanddepressionarenaturalres
Bothaperson’sheredityandhissurroundingshelptoshapehischaracter.
The______ofemotionalandpsychiatricdisordersthatcanpromptapersontoseektherapyiswide.
FamedsingerSteveWondercan’tseehisfansdancingathisconcerts.Hecan’tseethehandsofhisaudienceastheyapplaudw
随机试题
简述重要性与审计风险。
并发性是指两个或多个事件_______发生。
冠状动脉粥样硬化不会导致
有助于中毒性菌痢和流行性乙型脑炎鉴别的评估资料是
维生素D缺乏性佝偻病最早出现的骨骼改变是
通常由商业银行等开户代理机构代理证券登记结算公司为投资者开立证券账户。商业银行直接为投资者开立资金结算账户。( )
张老师每周的周一、周六和周日都跑步锻炼20分钟,而其他的日子都跳绳锻炼20分钟。某月他总共跑步5小时,那么这个月的10日是:
某企业拟进行一项固定资产投资项目决策。设定折现率为12%,有四个方案可供选择,其中甲方案的项目计算期为10年,净现值为1000万元、(A/P,12%,10)=0.177;乙方案的净现值率为一15%;丙方案的项目计算期为11年,其年等额净回收额为150万元
Playistheprincipalbusinessofchildhood,andmoreandmoreinrecentyearsresearchhasshownthegreatimportanceofplayi
A、HewantsothercountriestounderstandtheU.S.B、Hecallsonsomebigcompaniestocareaboutclimate.C、Hecallsonpeoplei
最新回复
(
0
)