It’s not what Thomas McKay sees in this machine, but what the machine sees in him that determines how well his eyes view the wor

admin2015-02-12  21

问题     It’s not what Thomas McKay sees in this machine, but what the machine sees in him that determines how well his eyes view the world. McKay is demonstrating a prototype device that sends a hundred thousand beams of light into his eye to measure the focusing accuracy of his eye’s lens. As those beams travel into the eye, they’re reflected off the retina, and as they come back they are bent a little bit according to the refracted abnormalities inside the eye. By calculating how accurately the eye’s lens bends the light, the Visx machine can determine how much correction the eye needs to see normally—without a patient ever looking at an eye chart.
    It’s called wave front technology. Physics professor Josef Bille pioneered it at the University of Heidelberg in Germany, twenty-five years ago, as a way to counter atmospheric distortion in telescopic images. He was brilliant enough to know the implications of his findings, and soon eye doctors noticed the possible applications in their field.
    There are a surprising number of eye doctors who know about the new technology but still insist upon their eye charts. Are they merely luddites who resist technological progression? Not really. Many are acutely aware of the limitations. I myself am no expert in this field, but I do know that human vision is more complex than how well our eyes bend light. It would be an oversimplification to simply look at the optical system of the eye and say we have the best correction. Visx wave front technology is a useful tool but optometrists may not yet be ready to throw away eye charts.
When the retina reflects the beams, what occurs?

选项 A、Patients have trouble seeing.
B、The ability to focus is gone.
C、No correction is needed.
D、The lens bends the light beams.

答案D

解析 属事实细节题。第一段第三句告诉我们,当光束从视网膜反射回来时,由于眼睛内部的屈光畸形,反射的光束有些弯曲。
转载请注明原文地址:https://kaotiyun.com/show/sOK4777K
0

最新回复(0)