1、大閱讀第 43 天老師醫(yī)學(xué)考博英語網(wǎng)絡(luò)課程Looking goodNot many of us have perfect eyesight, and we will all develop problems as weget older. Until recently, glasses or contact lenses were just about the only options. But as weve learned more about the eye, weve come up with some surprising newways to preserve or enhance

2、 vi, from changing what you eat to softwaret letsyou read your smartphithout reading glasses.The lenses in our eyes get stiffer as we age, making irder to focus on thingst are close up. This is why people start to need reading glasses from their 40sonwards. Eventually, nearly everyill own a pair. Bu

3、t it can be a pain putting onyour glasses every time you look at your phone, for instance, aremember where you put them.ming you canGlasses work by partly focusing light before it hits the eye so if you are lookingat a screen, why not make it do the focusing for you? A team at the MassachusettsInsti

4、tute of Technology has shownt plastic screen covers can correct for all kindsof viproblems effectively, the screen wears the glasses. But rathern makingplastic covers tailored to individuals eyes, the team want to exploit the ability ofexisting 3D screens to control the direction of light. The idea

5、ist instead ofproviding a 3D image, users could adjust the screen settings to “pre-focus” light astheir eyes require.Few handheld devihave 3D screens so far, but something similar can be done with software alone. “We know how the eye works so we mathematicallyinvertt and compute the image,” says Dan

6、iel Aliaga, a computer viresearcherat Purdue University in West Lafayette,na, who helped develop the idea. Thesoftware distorts images on the screen in such a wayt it mimics the effect of alens bending the light rays before they reach the eye. “It looks weird to anyone elsebut to you it looks sharp,

7、” says Aliaga.The approach works with both text and images, he says, so with pre-focused screens people would no longer need reading glasses. The Purdue teams start-up,called CPrecisely, is develoappst can modify the text on ebooks, phones andcomputers. Theproduct, a free alarm clock phone app, is d

8、ue for release thisyear. “Imagine youre in bed and you want to see what time it is,” says Aliaga.“Instead of searching for your glasses you just pick up your phone.”During the second world war, British propagandists circulated rumourst RAFpilots were such good night frs because all the carrots they

9、ate helped them to seehe dark. In reality the British were trying to keep their use of radar secret.Yet it turns outt there is some truth to the ideat diet can affect our eyes.Retinal cells contahree yellow pigments lutein, zeaxanthin and meso-zeaxanthin which absorb near-ultraviolet light, protecti

10、ng the eye from its damaging effectsand reducing glare. Thesgments are concentratedhe centre of the retinatproduthe sharp central area of our vi, the macula. “Its like wearingernalsunglasses,” says Billy Hammond of the University of Geia in Athens. “It reduthe lightensity and absorbs scatter.”We get

11、 thesgments from food, and the richer our diet ishem, the higherthe levels in our macula.heory then, people of any age could boost their eyesightby improving their diet or taking supplements. A large trial of supplements is due tofinish in July, but a smaller one, in which 36 people took a pill cont

12、aining all threepigments every day for six months, has already yieldeditive results.The effect was big enought people should have noticed the difference whencowith the glare of car headlights at night, for instance, saymember JohnNolan, a nutrition and viIreland.researcher at Waterford Institute of

13、Technology inNolan says boosting macular pigment levels should be even bettern wearingyellow-ted glasses for driving at night, as some people do, because such glassesblock blue light from the whole of the retina. Extra macular pigment, by contrast,doesnt stop the light reaching the retinal cells out

14、side the macula, so peripheralviis not reduced.Nolan already takes the supplements himself, and thinks taking all three isimportant. Hammond, however, thinks it is best to get these compounds from yourdiet, by eating plenty of vegetables kale, spinach and red peppers are among thebest sour. Eggs are

15、 another. “We like things to seem like drugs, but youd alwaysbe better off just eating some spinach,” Hammond says.A diet rich in macular pigments could not only improve your sight, it mightactually save it. As we get older the retinal cells in the macula oftenedamaged. As the disease progresses, pe

16、ople develop a blurred patchhe centre oftheir vit gets worse. Over a quarter of over-75s have macular degeneration,making it the biggest cause of blindness in Western countries.As there is no cure, the best approach is to detect macular degeneration earlyand try to stop it progressing.ltale yellow spots appearhe tie underlyinghe early stagesthe retina before symptoms appear. Trials have shownt peopleof the disease who take supplements of macular pigments, vitamins C and E, and zincare 25 per cent less likely to suffer deteriorationheir vi.1. distort 英vt.歪曲，dst:t美 dstrt； 曲解； 使變形；vi.； 變形