♪ ♪ go ♪ go ♪ tonight. >> i immediately thought that something was wrong with her eyes. >> the little girl whose world was fading into darkness. >> please fix my eyes, amen. >> young woman with dreams of seeing the stars. the rare disease stealing their sight. >> look at mama. >> she can't see. >> our bob woodruff with the incredible medical break through, giving hope and a vision for the future. >> i can see! >> this special edition of "nightline," miracle of sight, will be right back.

"nightline," miracle of sight, continues. here now, bob >> other than the sun, i've never seen a star, like ever. >> reporter: imagine a world without starlight. >> i've been told all my life, my vision's going to go. it's happening. and i get really scared. >> reporter: a world without detail. >> i couldn't really see the,

um, castle, because it was so dark. >> i immediately thought that something was wrong with her eyes. knowing that both my husband and i gave her a mutated gene. >> reporter: tonight, two incredible journeys. >> please fix my eyes. amen. >> reporter: one revolutionary new drug. >> this was an eureka moment. just knock your socks off. >> reporter: and a race against time to stop the world from going dark. >> if i had the chance to save her vision, sign me up. >> i can't believe it's finally happening. ♪ happy birthday to you ♪ >> reporter: 6-year-old monroe lee dreams like many other little girls, in visions of pink and princesses. >> plblow it out. >> reporter: but monroe isn't like most little girls because

her dreams just don't match her reality. >> i couldn't really see in the dark. >> reporter: did she explain this to her friends? >> monroe can't see in the dark. >> reporter: she suffers from a rare genetic disease which means she'll eventually go blind, for a child who loves horse racing. >> he won, he won! >> reporter: and disney, everything disney, that means never experiencing the glowing wonder of cinderella's castle at night. >> i couldn't really see the um, castle, because it was so dark. >> hi, pretty girl. >> reporter: monroe's mom says she noticed immediately that something was wrong when monroe was just a baby. >> hi. >> reporter: and it got worse. monroe kept missing key milestones. at 18 months, she's still not walking. >> still not walking. she did this little scoot jump like crawl. she would scoot jump into walls. >> reporter: it wasn't until she was 3 years old that they

learned her diagnosis, a genetic mutation inherited from her parents. only about 2,000 people in the whole country have it. >> it was scary. it was scary. i mean, knowing husband and i gave her a mutated gene. >> reporter: this is an extremely rare condition. >> we both blamed ourselves for a long time. >> reporter: while her family has given her the best childhood possible, they know time is precious. >> if monroe wanted to do it, we did it, because tomorrow wasn't promised. i didn't know if i'd wake up one day and she won't be able to see at all. >> look at mama. she can't see very well. >> reporter: just 30 miles away, college rower heather is going through the same thing. >> people always tell me they can't tell i'm blind. and i think that comes down to me being used too it all my life

and not letting it stop me from anything. >> reporter: for the 25-year-old, life is one big blur. as a child, she was diagnosed with the same genetic disease monroe has. >> congenital amoreosis is the name of it. i try not to think about it. >> reporter: the main issue with lca is light sensitivity. heather can't see anything at night, a tough thing for someone who wants to be an astro physicist and study the stars. you have no idea what they look like. >> i've only seen them in pictures. >> reporter: even on the brightest day, heather sees just a fraction of what other people do, using her guide dog luna, to get around. >> i can see most of the trees like where they're at, kind of as blobs. things that are tall. and i can tell them different than the buildings. >> reporter: shadows and shade are a constant enemy. >>i i've tripped a few times an

had a mini heart attack when you trip going downstairs. >> when she walks in, there's been times i didn't know it was her. so i might make a little comment to get her to say something. you didn't know that. did you? >> no, i never noticed that. >> when she was smiling i could tell. i could see the white of the teeth. i see where her eyes are, but i can't see her eyes. >> reporter: heather uses a variety of tools, high tech. >> i have to invert for writing. >> reporter: and low tech. >> my felt-continue marker. my recipes on my ipad so i can see it good. >> reporter: but her biggest helper is fiance christian. >> i don't know if i've ever seen his eye color. i've tried to look at him super close in the sun. i've never been able to see a blemish or anything on his face. >> she always looks for the best in things. i want to be with her, you know, knowing she's like that.

>> i'm scared to not be able to see christian's face or our future children's faces. i've wanted to be a mother all my life. so i want to be able to at least see their faces. >> reporter: she was giving up hope when suddenly, she got a call. how did you get the word? >> i was asleep one morning, and my dad called me. are you awake? like, there's this thing on tv, a cure for the blind, check it out. i think it's your disease. >> reporter: it started in this medical lab in philadelphia, with a ground-breaking new drug. for almost as long as they've been married, doctors jean bennett, a gene therapy researcher and albert mcguire, an eye surgeon have been searching for a cure to genetic blindness. >> at that point in time, the technology did not exist. >> reporter: if were you older and more experienced than this, would you have realized this was almost impossible. >> yeah, it was a good thing not knowing, because it would be daunting like this is ridiculous. >> reporter: eventually, technology caught up.

dr. bennett figured out a way to replace the gene that cause people like heather and monroe to go blind. rpe-65. and dr. mcguire figured out how to inject the replacement into the patient's eye. the treatment now called luxturna, the first-ever gene therapy approved by the fda. >> then the next question was, wow, wouldn't it be amazing if we could make blind children see? >> reporter: heather and monroe quickly signed up and landed at children's hospital los angeles. dr. aaron miguel will handle both surgeries. >> it is changing the course of the disease in a way we never have seen before. never thought possible. >> reporter: how both oop ratio operations are the same, results are different. >> monroe may have more stable improvements over the long time compared to heather because of her age may have lost more tissue. >> reporter: making the desis to

risk what eyesight they have left is a big deal. enter christian gardeno. ♪ well ♪ i ♪ ♪ had you >> reporter: millions fell in love with him on season 12 of america's got talent, where he earned the coveted golden buzzer. when he was 12, christian was chosen for dr. bennett and dr. mcguire's clinical trial. was this a tough call? >> no. >> reporter: what's the very first thing that you saw? >> i think it was my parents, my, my parents aface in detail. that was pretty incredible. >> reporter: before surgery, doctors recorded christian trying to navigate a maze. you can see he has trouble staying in line. missing steps and running into barriers. after treatment, christian saw things he'd never seen before, maneuvering around the obstacles, flawlessly. >> massive, massive improvement, yeah. i'd take anything of what i have

now over what i had before. >> reporter: after months of waiting, it's heather's chance to gain something she's always wanted. >> my hope's that i'm afraid too admit, to see a star and to be able to see christian's face, actually see his eye color. i have an appointment at the vision center. >> reporter: it will take two operations, a week apart, one for each eye. her left eye is up first. heather's dad and step mom arrive. >> i put a little mark above your left eye. >> it's still hard. >> look at you. >> my vision doesn't define who i am. but it's kind of made me who i am. i don't know how to not be the blind girl. >> are you calm? >> i'm shaking. >> reporter: the operation itself will last about an hour.

>> the luxturn a goes underneath the retina. we use a fine needle to deliver a small amount under the retina. there's no room for error. >> reporter: dr. miguel threads that delicate needle and her father and fiance wait. >> i love you, baby. >> reporter: for monroe, the surgery could be a chance at a normal childhood. >> she was afraid. she didn't know what to expect. but i do know that she was scared. just to see my baby being wheeled back, praying that i'm making the right decision. praying that the end result is going to be what we hope it will be. >> reporter: post surgery, they both have to wear a protective eye patch for 24 hours, and then that first moment of truth. when she took that patch off of

her eye, what did she see? >> nothing. >> reporter: i mean, black? >> yeah, it was black. she kept saying i couldn't see, i can't see. >> we're going to check your vision. >> i'm scared to open it. do you see my hand moving here? >> reporter: stay with us. a wor? scrub less with dawn ultra. it's superior grease-cleaning formula gets to work faster. making easy work of tough messes. dawn is a go-to grease-cleaner throughout the kitchen, too. keep a bottle in the laundry room to pre-treat greasy stains. and keep dawn in the garage to lift grease off car rims. it's even gentle enough to clean wildlife affected by oil. dawn's grease cleaning power takes care of tough grease wherever it shows up. scrub less and save more... with dawn.

[coughs] kim is now demonstrating her congestion. save it, slimeball. i've upgraded to mucinex. we still have 12 hours to australia. mucinex lasts 12 hours, so i'm good. now move- kim nooooo!! mucinex has a patented tablet that lasts 3x longer, for 12 hours. introducing a razor that works differently. the gillette skinguard has a guard between the blades that helps protect skin. the gillette skinguard. you want a fresh-smelling home, but some air fresheners use heavy, overwhelming scents. try febreze one; a range of innovative air fresheners with no heavy perfumes that you can feel good about using in your home to deliver a light, natural-smelling freshness.

febreze one neutralizes stale, stuffy odors and releases a subtle hint of fragrance like bamboo or lavender & eucalyptus. to eliminate odors with no heavy perfumes, try febreze one. brand power. helping you buy better. ♪ do you recall, not long ago ♪ we would walk on the sidewalk ♪ ♪ all around the wind blows ♪ we would only hold on to let go ♪ ♪ blow a kiss into the sun ♪ we need someone to lean on ♪ blow a kiss into the sun ♪ we needed somebody to lean on ♪ ♪ ♪ ♪ all we need is someone to lean on ♪

a former army medic, made of the we maflexibility to handle members like kate. whatever monday has in store and tackle four things at once. so when her car got hit, she didn't worry. she simply filed a claim on her usaa app and said... i got this. usaa insurance is made the way kate needs it - easy. she can even pick her payment plan so it's easy on her budget and her life. usaa. what you're made of, we're made for. usaa a lot's changed since you were here. it's called the internet. i'm gonna hit start now, ok? me back!

"nightline," miracle of sight, continues. here again, bob woodruff. >> reporter: heather is scared. over the course of the next few days, her life is going to change forever. for better or for worse. >> it was the longest night ever. >> reporter: the 25-year-old is

recovering from surgery, to see if the first-ever approved live gene therapy can restore her eyesight. >> we're going to check your vision. >> i was really nervous when we took the patch off that day. >> can you move your eye again for me. >> it was really scary. and when i couldn't see the nurse's hand going back and forth, i kind of panicked. >> do you see my hand moving here? >> no. not really. >> did i really try to fix my eyes and make them worse now? >> hey, heather. >> hello. >> is this backfiring? >> let me have a look. >> very blurry. >> very blurry. all right. look straight. up and left. excellent. looks perfect. all the medicine's absorbed, okay. you do have an air bubble. >> and that's what causes the blurriness? >> yes. that's why it's sao blurro blur.

>> reporter: dr. nigel isn't alarmed. he says the day after surgery is always rough. but, by the end of that first week, she was reconsidering whether to have the second operation at all. to fix her other eye. >> i still can't see the same as before surgery, like my vision is still worse. >> reporter: but she decided it was worth the risk. >> heather, this is dr. nigel. i know you're just waking up. everything looks so perfect, okay? just like the other eye. we'll let you relax a little, all right? and i'll see you tomorrow morning. okay. great. >> reporter: nearly all the major improvements will happen in the first month after both surgeries. >> he likes it! >> reporter: and monroe's progress has been incredible. >> i can see in the dark! >> what, baby? >> i can see in the dark! >> reporter: so after surgery, i

imagine it's pretty shocking? >> she's a whole new girl. >> one, two, three. >> reporter: born again? >> born again. >> five. >> reporter: does she realize this? >> oh, 100%. >> what do you see? >> cars in the dark! >> reporter: the treatment opening up a whole new world for the little girl, a world she'd never seen before. >> where do you want to go? okay, show me the way, babe. which one is your favorite princess? >> belle. >> come on. >> reporter: in fact, on this day, monroe has gone to transform into a princess. [ applause ] wonders never cease for the 6-year-old fan. >> princesses have never been on this ride. this is different. >> those have always been the same, honey, you just couldn't see them before.

>> everything was worth it. my baby could see. >> reporter: every minute, every dollar? >> everything. >> reporter: all worth it. >> 100%. >> reporter: almost two months after surgery, heather was still struggling to really see the impacts. >> the recovery process is much harder for me than i expected. my light sensitivity, especially at night, which i got really excited about. >> reporter: what can you see right now? we decided to test out heather's eyes in the dark. one of her dreams was to walk on the beach at night. can you turn off the light completely? >> just give my eyes a second. let them adjust a little. i see that light, it looks like it's glowing almost, like there's a reflection maybe on the bottom? what's over this way? i'm not sure if that's something. >> reporter: those are just two white lines there of the waves. >> holy moly, i see those a lot, like two lines right there. >> reporter: you can?

>> i can't believe it. i see the glare, is that the moon? >> reporter: yes. >> i saw the glare from the moon! this is crazy. i hear the water coming. >> reporter: can you see it. >> i do. it's like right there. i do see that. and there's a little second one coming. >> reporter: yes, exactly. that's awesome! is one of your dreams to see the stars? >> oh, yes, definitely. it's always been a dream of mine. kind of waiting, because i'm afraid i won't be able to. >> reporter: now she will get that chance. >> so i set up two telescopes. >> reporter: thanks to john isaacs, who set up some telescopes in his back yard for us. john decides to start with the moon. if heather cannot see something that large through the scope, she will never be able sar. >> the lights are not helping. >> reporter: now the real moment

of truth. john repositions to look at sirius, the brightest star in the sky. if you have 20/20 vision, you clearly see the star here in our video, with the naked eye. for heather, her only hope is through this telescope, after 25 year of waiting. >> so are you seeing it yet? >> a gray spot, oh, i see it! >> you do? are you okay? >> yeah. i see it. i can't even talk. it doesn't seem real, like i can't believe i'm seeing a star for the first time ever. oh, my god. it's amazing. >> okay. >> thank you. >> yeah. >> reporter: we'll be right back.

(thud) (crash) (grunting) (whistle) play it cool and escape heartburn fast with tums chewy bites cooling sensation. ♪ tum tu-tu-tum tums i'climate is the number 1ove cpriority.sage.on. i would declare a state of emergency on day 1. congress has never passed an important climate bill, ever. this is a problem that continues to get worse. i've spent a decade fighting and beating oil companies... stopping pipelines... stopping fossil fuel plants, ensuring clean energy across the country. how are we going to pull this country together?

we take on the biggest challenge in history, we save the world and do it together. ♪ work so hard ♪ give it everything you got ♪ strength of a lioness ♪ tough as a knot ♪ rocking the stage ♪ and we never gonna stop ♪ all strength, no sweat. ♪ just in case you forgot ♪ all strength. ♪ no sweat secret. all strength. no sweat.

ithere's my career...'s more to me than hiv. my cause... and creating my dream home. i'm a work in progress. so much goes into who i am. hiv medicine is one part of it. prescription dovato is for adults who are starting hiv-1 treatment and who aren't resistant to either of the medicines dolutegravir or lamivudine. dovato has 2 medicines in 1 pill to help you reach and then stay undetectable. so your hiv can be controlled with fewer medicines while taking dovato. you can take dovato anytime of day with food or without. don't take dovato if you're allergic to any of its ingredients or if you take dofetilide. if you have hepatitis b, it can change during treatment with dovato and become harder to treat. your hepatitis b may get worse or become life-threatening if you stop taking dovato.

so do not stop dovato without talking to your doctor. serious side effects can occur, including allergic reactions, liver problems, and liver failure. life-threatening side effects include lactic acid buildup and severe liver problems. if you have a rash and other symptoms of an allergic reaction, stop taking dovato and get medical help right away. tell your doctor if you have kidney or liver problems, including hepatitis b or c. don't use dovato if you plan to become pregnant or during the first 12 weeks of pregnancy since one of its ingredients may harm your unborn baby. your doctor should do a pregnancy test before starting dovato. use effective birth control while taking dovato. the most common side effects are headache, diarrhea, nausea, trouble sleeping, and tiredness. so much goes into who i am and hope to be. ask your doctor if starting hiv treatment with dovato is right for you.

what game are you guys playing? >> princesses. >> do you love to hula-h >> mama, i did

>> this is monroe. >> hi. >> can i have a hug? thank you for meeting me.

kerrygold has a taste so rich it can take you to ireland's lush, green pastures. where grass-fed cows produce rich, creamy milk for a truly delicious taste. kerrygold. the taste that takes you there.