1 00:00:01,800 --> 00:00:04,320 Speaker 1: Welcome to brain Stuff, a production of I Heart Radio, 2 00:00:06,600 --> 00:00:10,080 Speaker 1: Hey brain Stuff Lauren Bobi Bam here. The old saying 3 00:00:10,280 --> 00:00:13,680 Speaker 1: sleep with one eye open isn't so metaphorical for everyone. 4 00:00:14,520 --> 00:00:17,759 Speaker 1: Take for example, Mel mom in Kansas whom How to 5 00:00:17,920 --> 00:00:19,880 Speaker 1: Work spoke with via email for the article that this 6 00:00:19,920 --> 00:00:22,560 Speaker 1: episode is based on. Well, she has a son who 7 00:00:22,600 --> 00:00:26,800 Speaker 1: regularly sleeps with both eyes about half open, and she said, oh, 8 00:00:26,880 --> 00:00:28,920 Speaker 1: we joke around and say that Jack is afraid he's 9 00:00:28,920 --> 00:00:32,240 Speaker 1: going to miss something. The family wasn't too weird a 10 00:00:32,280 --> 00:00:34,199 Speaker 1: doubt when he started doing it, though, as they had 11 00:00:34,240 --> 00:00:37,480 Speaker 1: experienced it with an older daughter. Mel said, a long 12 00:00:37,520 --> 00:00:40,320 Speaker 1: time ago, we asked the doc. He said kids usually 13 00:00:40,360 --> 00:00:43,480 Speaker 1: grow out of it. In her daughter's case, this wound 14 00:00:43,600 --> 00:00:46,479 Speaker 1: up being true, but it's not unusual for people to 15 00:00:46,520 --> 00:00:51,320 Speaker 1: sleep with an eye or two open indefinitely. The condition 16 00:00:51,440 --> 00:00:54,960 Speaker 1: is known in medical circles as nocturnal lack ofthalmus, and 17 00:00:55,120 --> 00:00:58,240 Speaker 1: is characterized by the inability to completely close the eyelids 18 00:00:58,240 --> 00:01:01,680 Speaker 1: while sleeping. Most people are unaware that they're sleeping this 19 00:01:01,720 --> 00:01:04,560 Speaker 1: way until someone tells them, but they may wake up 20 00:01:04,600 --> 00:01:09,720 Speaker 1: feeling tired or experiencing eye pain. As much as of 21 00:01:09,720 --> 00:01:13,320 Speaker 1: the population has experienced nocturnal lack of thalmus. It's a 22 00:01:13,400 --> 00:01:16,399 Speaker 1: variation of the wider condition of lack of thalness, which 23 00:01:16,440 --> 00:01:19,800 Speaker 1: describes any circumstance where you can't close your eyelids completely 24 00:01:19,920 --> 00:01:23,479 Speaker 1: even when you're trying. It's usually caused by an improperly 25 00:01:23,520 --> 00:01:27,520 Speaker 1: functioning seventh cranial nerve, the facial nerve that's responsible for 26 00:01:27,560 --> 00:01:31,120 Speaker 1: the muscles that control the movement of both eyelids and eyebrows. 27 00:01:32,880 --> 00:01:36,400 Speaker 1: That improper functioning can be triggered by a litany of issues, 28 00:01:36,720 --> 00:01:40,720 Speaker 1: like trauma to the face or the skull, a thyroid disease, tumors, 29 00:01:40,800 --> 00:01:44,840 Speaker 1: or damage from infections, among other things. Sometimes simple heredity 30 00:01:44,920 --> 00:01:49,120 Speaker 1: is the culprit. Whatever the cause, it's unlikely that anyone 31 00:01:49,240 --> 00:01:51,760 Speaker 1: is able to get good sleep with their eyes wide open. 32 00:01:52,480 --> 00:01:55,640 Speaker 1: That's because your eyes need to close or at least blink, 33 00:01:55,920 --> 00:02:00,160 Speaker 1: in order to keep your eyes lubricated and healthy. House 34 00:02:00,200 --> 00:02:03,160 Speaker 1: of Works also spoke by email with Dr Ivan Schwab, 35 00:02:03,200 --> 00:02:07,840 Speaker 1: a clinical spokesperson for the American Academy of Optimology. He explained, 36 00:02:08,200 --> 00:02:10,600 Speaker 1: as far as I know, few people, if any, could 37 00:02:10,600 --> 00:02:13,520 Speaker 1: sleep with their eyes fully open, because as you sleep, 38 00:02:13,560 --> 00:02:17,040 Speaker 1: the upper lid muscles will relax and close, but if 39 00:02:17,080 --> 00:02:20,400 Speaker 1: there were no upper lid coverage available, it might be possible, 40 00:02:20,440 --> 00:02:23,239 Speaker 1: but would be difficult to sleep and quite detrimental to 41 00:02:23,280 --> 00:02:27,720 Speaker 1: the eye with drying on the surface I surface drying 42 00:02:27,880 --> 00:02:31,320 Speaker 1: is an uncomfortable problem that causes a burning sensation that 43 00:02:31,440 --> 00:02:33,280 Speaker 1: may even wake you up in the middle of the night. 44 00:02:33,919 --> 00:02:38,440 Speaker 1: This drying and irritation is called exposure carrotitis. If it 45 00:02:38,480 --> 00:02:42,560 Speaker 1: becomes really problematic, there are options. The Schwab said the 46 00:02:42,560 --> 00:02:45,560 Speaker 1: best way medically is to apply ointment and tape the 47 00:02:45,600 --> 00:02:49,359 Speaker 1: lids closed, over that these measures must be done each night. 48 00:02:50,080 --> 00:02:53,079 Speaker 1: In many, but not all cases, there are surgical options 49 00:02:53,120 --> 00:02:55,680 Speaker 1: to raise the lower lid or lower the upper lid. 50 00:02:56,639 --> 00:02:58,919 Speaker 1: There are also special eye goggles that can be worn 51 00:02:58,960 --> 00:03:03,480 Speaker 1: at night to keep the eyes moist. However, although this 52 00:03:03,600 --> 00:03:06,640 Speaker 1: is a problem in humans, a number of other animals 53 00:03:06,720 --> 00:03:10,000 Speaker 1: evolutionarily developed the ability to sleep with one eye open. 54 00:03:10,840 --> 00:03:14,320 Speaker 1: This is called un hemispheric sleep. Half the brain stays 55 00:03:14,320 --> 00:03:18,240 Speaker 1: awake while the other half sleeps. Animals like fruit backs, porpoises, 56 00:03:18,280 --> 00:03:21,639 Speaker 1: bottlenose dolphins, and birds are known to do this, likely 57 00:03:21,720 --> 00:03:24,359 Speaker 1: because as potential prey, they need to be able to 58 00:03:24,440 --> 00:03:28,200 Speaker 1: stay partially alert in order to stay safe. In these cases, 59 00:03:28,320 --> 00:03:31,239 Speaker 1: the open eye blinks as normal so it doesn't dry 60 00:03:31,280 --> 00:03:38,400 Speaker 1: out in today's episode is based on the article can 61 00:03:38,440 --> 00:03:40,440 Speaker 1: You Fall Asleep with your Eyes Open? On how stuff 62 00:03:40,440 --> 00:03:43,040 Speaker 1: Works dot com written by Leo Hoyt. A brain Stuff 63 00:03:43,080 --> 00:03:44,960 Speaker 1: is production of I Heart Radio in partnership with how 64 00:03:45,000 --> 00:03:47,160 Speaker 1: stuff Works dot Com, and it's produced by Tyler Klang. 65 00:03:47,760 --> 00:03:50,240 Speaker 1: For more podcasts for my heart Radio, visit the iHeart 66 00:03:50,320 --> 00:03:52,880 Speaker 1: Radio app, Apple Podcasts, or wherever you listen to your 67 00:03:52,920 --> 00:04:01,680 Speaker 1: favorite shows.