1 00:00:01,920 --> 00:00:06,360 Speaker 1: Welcome to brain Stuff production of I Heart Radio. Hi 2 00:00:06,519 --> 00:00:09,440 Speaker 1: brain Stuff, Lauren bogel Bam here with another classic episode 3 00:00:09,480 --> 00:00:14,680 Speaker 1: from our podcast archives. The world is increasingly near sighted, 4 00:00:15,000 --> 00:00:18,840 Speaker 1: and I'm not talking metaphorically. Researchers say that by the 5 00:00:18,920 --> 00:00:22,280 Speaker 1: year twenty fifty half of the world will be near sighted. 6 00:00:22,840 --> 00:00:28,800 Speaker 1: Today's question is why, Hey, brain Stuff, Lauren bogel Bam here, 7 00:00:29,200 --> 00:00:33,600 Speaker 1: there's a myopia epidemic going on. In n seventy two, 8 00:00:33,760 --> 00:00:37,880 Speaker 1: about of Americans aged twelve to fifty four were diagnosed 9 00:00:37,880 --> 00:00:41,040 Speaker 1: with this condition, which is also called near sightedness. But 10 00:00:41,120 --> 00:00:45,560 Speaker 1: today some forty of young Americans are receiving the same diagnosis. 11 00:00:46,080 --> 00:00:49,599 Speaker 1: And that's nothing compared to Asian countries, where of high 12 00:00:49,640 --> 00:00:53,040 Speaker 1: school kids are now near sighted. In seal, ninety six 13 00:00:53,120 --> 00:00:56,160 Speaker 1: point five percent of nineteen year old males are myopic, 14 00:00:56,960 --> 00:00:59,880 Speaker 1: and researchers say that by the year twenty fifty five 15 00:01:00,080 --> 00:01:03,320 Speaker 1: billion people will be wearing glasses to combat near sightedness. 16 00:01:03,360 --> 00:01:05,720 Speaker 1: That's more than half the people in the world. How 17 00:01:05,720 --> 00:01:08,960 Speaker 1: did this happen so fast and so many people. While 18 00:01:09,040 --> 00:01:11,319 Speaker 1: intuitively you might think it has something to do with 19 00:01:11,360 --> 00:01:14,520 Speaker 1: all the time we spend staring at computer or smartphone screens, 20 00:01:14,800 --> 00:01:17,039 Speaker 1: it's not so cut and dried. The rise and near 21 00:01:17,080 --> 00:01:20,399 Speaker 1: sightedness started happening before the prevalence of those screens, and 22 00:01:20,480 --> 00:01:23,640 Speaker 1: has been studied at least since the nineteen sixties. The 23 00:01:23,720 --> 00:01:26,880 Speaker 1: latest research reveals that the world's rising myopia rates stem 24 00:01:26,920 --> 00:01:30,800 Speaker 1: from spending too much time indoors. In general, several studies 25 00:01:30,800 --> 00:01:34,120 Speaker 1: show the less time children spend outdoors, the more likely 26 00:01:34,160 --> 00:01:37,240 Speaker 1: they are to develop myopia. This could explain the much 27 00:01:37,319 --> 00:01:40,560 Speaker 1: higher myopia rates in Asian countries, where a stronger focus 28 00:01:40,560 --> 00:01:44,000 Speaker 1: on education keeps kids indoors for more hours than children 29 00:01:44,000 --> 00:01:47,000 Speaker 1: living in most other parts of the world. We spoke 30 00:01:47,000 --> 00:01:50,800 Speaker 1: with Dr Adam Claren, a Florida optometrist. He said the 31 00:01:50,840 --> 00:01:53,720 Speaker 1: progression of the number of myoptic patients has risen too 32 00:01:53,760 --> 00:01:57,400 Speaker 1: fast to be explained by genetics alone. Unfortunately, the data 33 00:01:57,480 --> 00:02:00,200 Speaker 1: is not conclusive enough to determine what parts of being 34 00:02:00,240 --> 00:02:03,720 Speaker 1: outside is protective against myopia. Is that the sunlight, is 35 00:02:03,760 --> 00:02:06,160 Speaker 1: it looking at distant objects, or is it something we're 36 00:02:06,160 --> 00:02:09,880 Speaker 1: not even thinking about. Near sightedness is caused by an 37 00:02:09,880 --> 00:02:13,800 Speaker 1: elongated eyeball. Normally, the light that flows into your eyes 38 00:02:13,880 --> 00:02:16,880 Speaker 1: focused directly on the surface of the retina, but if 39 00:02:16,880 --> 00:02:19,360 Speaker 1: your eyeball is a bit too stretched out, the lens 40 00:02:19,400 --> 00:02:22,160 Speaker 1: will focus the lights slightly in front of the retina instead, 41 00:02:22,480 --> 00:02:26,720 Speaker 1: resulting in blurry vision. The hypothesis about myopia that's gaining 42 00:02:26,720 --> 00:02:29,960 Speaker 1: the most traction says that when the neurotransmitter dopamine is 43 00:02:30,000 --> 00:02:33,160 Speaker 1: released into the retina, it prevents your eyeball from elongating 44 00:02:33,200 --> 00:02:36,440 Speaker 1: and blurring your vision, and light is what stimulates this 45 00:02:36,520 --> 00:02:40,280 Speaker 1: release of dopamine. Normally, a pair of glasses or contact 46 00:02:40,360 --> 00:02:43,240 Speaker 1: lenses is all that's needed too sharpen your vision. However, 47 00:02:44,000 --> 00:02:46,520 Speaker 1: of those with the condition have a heightened form called 48 00:02:46,639 --> 00:02:49,639 Speaker 1: high myopia. People with high myopia are at a risk 49 00:02:49,680 --> 00:02:54,360 Speaker 1: for developing cataracts, glaucoma, torn or detached retinas, and even blindness. 50 00:02:55,200 --> 00:02:57,600 Speaker 1: Although no one knows how much time spent outdoors is 51 00:02:57,680 --> 00:03:01,120 Speaker 1: enough to forestall myopia, one researcher at the Australian National 52 00:03:01,200 --> 00:03:04,560 Speaker 1: University in Canberra estimated the amount at three or more 53 00:03:04,600 --> 00:03:08,280 Speaker 1: hours per day. It's also possible that strong indoor lights 54 00:03:08,280 --> 00:03:12,119 Speaker 1: could help, but Dr roheat Varma, director of the University 55 00:03:12,120 --> 00:03:15,280 Speaker 1: of Southern California I Institute, told us via email that 56 00:03:15,360 --> 00:03:17,799 Speaker 1: even if the myopia boom is not directly related, to 57 00:03:17,880 --> 00:03:21,080 Speaker 1: children spending more time indoors looking at a screen quote, 58 00:03:21,440 --> 00:03:24,200 Speaker 1: These are two sides of the same coin. Spending more 59 00:03:24,240 --> 00:03:28,000 Speaker 1: time indoors equates to spending less time outdoors, especially during 60 00:03:28,000 --> 00:03:31,640 Speaker 1: the day. Researchers are still trying to determine the real 61 00:03:31,680 --> 00:03:35,680 Speaker 1: fix for the myopia epidemic. Dr Claarin said other studies 62 00:03:35,680 --> 00:03:38,280 Speaker 1: have shown that a low dose of atropine eye drops 63 00:03:38,320 --> 00:03:41,280 Speaker 1: can also slow the progression of myopia. These studies are 64 00:03:41,320 --> 00:03:44,520 Speaker 1: completely unrelated to the studies on being outdoors, so there's 65 00:03:44,520 --> 00:03:48,920 Speaker 1: obviously more than one mechanism at play. Hopefully, continuing research 66 00:03:48,960 --> 00:03:57,640 Speaker 1: will shed some light on this growing problem. Today's episode 67 00:03:57,680 --> 00:03:59,760 Speaker 1: is based on the article half the World will be 68 00:03:59,800 --> 00:04:02,760 Speaker 1: near sited by fifty on how stuff works dot Com, 69 00:04:02,760 --> 00:04:06,240 Speaker 1: written by Melanie Radzekei McManus. Brain Stuff is production by 70 00:04:06,240 --> 00:04:08,560 Speaker 1: Heart Radio in partnership with how stuff Works dot Com 71 00:04:08,640 --> 00:04:11,680 Speaker 1: and is produced by Tyler Clay. Four more podcasts my 72 00:04:11,760 --> 00:04:14,960 Speaker 1: Heart Radio, visit the iHeart Radio app, Apple Podcasts, or 73 00:04:15,000 --> 00:04:16,760 Speaker 1: wherever you listen to your favorite shows.