Learning to see: How vision sharpens
September 19th, 2011
09:12 AM ET

Learning to see: How vision sharpens

Editor's Note: Sandra Aamodt and Sam Wang are the authors of Welcome to Your Child's Brain, a guide to what's really going on in the mind from conception to college.

Babies are born nearly blind. You may think that your newborn is gazing into your eyes, but what she actually sees is a vaguely face-shaped blur, associated with loving sounds and possibly milk. How she develops mature vision is mostly automatic, requiring involvement from you only at a few key points.

Though vision feels seamless, the brain constructs its image of the world from neural activity in dozens of interconnected regions that specialize in particular aspects of seeing. All these cortical areas are immature at birth, so babies’ acuity starts out forty times worse than adults’ and doesn’t become equal until four to six years of age. Indeed, an adult who could see as well as a newborn would have 20/600 vision.

The champion of the infant visual system is motion, which develops early and is relatively difficult to disrupt. At four weeks of age, babies can detect a flickering stimulus in a single location almost as well as adults. Babies can discriminate motion direction around seven weeks and speed by twenty weeks. Perception of global motion patterns, like raindrops seen through the windshield of a moving car, improves rapidly between three and five months and then continues to develop slowly through middle childhood. This aspect of motion processing, the most vulnerable to disruption, is impaired in some developmental disorders, including dyslexia, autism, fragile-X syndrome, and Williams syndrome.

From birth, babies are attracted to faces. Very young babies, though, are working from an approximate model of what a face looks like, as they will look at almost any round thing that has two “eyes” and a “mouth” in the right place. (This is not very surprising if you consider how poorly they see real faces.) By four or five months, their preferences are more realistic, and babies have begun to process faces differently from other objects. This change probably reflects maturation of the fusiform face area, a region in the temporal cortex specialized for face processing. This brain specialization enables ordinary adults to beat the world’s best computer programs in detecting subtle differences between faces. The fusiform face area is preferentially activated by faces already in two-month-old infants.

Visual experience influences the development of face-recognition expertise starting in infancy. Six-month-olds are as good at distinguishing individual monkeys as individual people, but by nine months, babies become better at identifying people and lose the ability to recognize monkey faces. During this period, babies also become better at distinguishing faces within their own racial group than within other racial groups, probably because most babies have more visual experience with their own group than with others. This process probably involves the sculpting of synaptic connections by experience to tune perception to the characteristics of the local environment.

Children whose vision is impaired by cataracts demonstrate the need for visual experience in the development of seeing. Babies who have cataracts from birth retain the poor acuity of newborns until their eye function is surgically restored, even as late as nine months of age. With experience, their acuity improves, but deprivation for the first three to eight months leads to acuity more than three times worse than normal at five years of age. Global motion perception is affected by cataracts only in the first three months of life.

So under most conditions, development of vision goes fine—though parents do need to watch out for exceptional cases needing further attention. Routine well-baby exams should catch most issues of this sort, but early treatment of any sensory deficit, if possible, will help to minimize later difficulties. Luckily, problems in visual development are the exception. In most cases, parents get a free ride and can simply sit back and watch their child’s new abilities grow.

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soundoff (48 Responses)
  1. cheryl

    how do they test what babies see? this is a real question, NOT intended as disparaging...just curious how they study it

    September 19, 2011 at 11:06 | Report abuse | Reply
    • Chris

      I'm no neuroscientist, but I'm betting they measure the activity in the regions of the brain that process visual input.

      September 19, 2011 at 14:31 | Report abuse |
    • eyedoc

      Visual evoked potential, which monitors changes in brain activity as a stimulus is shown. Preferential looking or "Teller" cards, which work on the basis that infants naturally look towards a more visually interesting stimulus (black and white lines vs. solid gray).

      September 19, 2011 at 14:59 | Report abuse |
  2. Des Welch

    My friend's child (who is 10) has struggled in school from day one. She has had his eyes tested multiple times and the diagnosis is always the same, his eye sight is fine. He continued to complain about reading, saying that the words "move" and that he gets headaches when he reads. She decided to take him to a opthamologist who tested him with a new visual aid that apparently helps regulate the speed at which the information enters the eye (that's the best way I can describe it). The results were immediate, he could tell a difference right there in the office. He has been fitted for the lenses and my friend said that they have made a world of difference in the past month, his teachers have noticed and his confidence has soared. My friend is so thrilled, I can hear the relief in her voice. Wish more people knew about this, at least to get tested to see if it could help their kids or themselves because they would know right away. The company that makes them is called Chromagen Vision, not sure if every opthamologist carries them.

    September 19, 2011 at 11:17 | Report abuse | Reply
    • nemommy

      I think you are referring to Irlen Syndrome. Some opthamologists subscribe to this belief, some do not.

      September 19, 2011 at 12:29 | Report abuse |
    • Des Welch

      No this isn't Irlen, its that basic idea taken to the next level or "generation" might be a better word.

      September 19, 2011 at 13:56 | Report abuse |
    • Anon

      Irlen and Chromogen are both scams.

      September 19, 2011 at 15:39 | Report abuse |
    • snow

      May be that they are considered scams in academics.. But, how do you explain the improvement in the kid? that could not have been faked by the doctor just to prove his stand..

      I do not think anyone should take a hard stand on anything medical (as long as there are no detrimental effects). If a particular method does not help, move on to something else. if it does, well, thats what you want.. isnt it?

      Medical field is not a pure science. In science, for any machine, if you give the same input, the output will always be the same. Not in medicine. It is merely a collection of experimental data put togather over the course of centuries.

      September 19, 2011 at 17:03 | Report abuse |
    • Des Welch

      Snow, very eloquently stated. My friend's kid has been helped so much, I just had to share. This is something that you can be tested for and see immediately if it works or not, right in the doctor's office. If it works for you it works, if it doesn't, it doesn't, nothing scammy about it. Just hate that people who could really be helped would be turned off before they even know about it.

      September 19, 2011 at 19:16 | Report abuse |
    • Tom

      Snow and Des, I bet you two are either the same person or you both work in the same office that sells chromogen. Great sales pitch from you both unless you are the same person.

      September 19, 2011 at 22:59 | Report abuse |
    • Eyes

      Just doing a favor so everyone can hear about how well "your friends child (age 10" did? I mean seriously? You couldn't at least come up with a fake name or gender? Or at least claim it was your kid? Wow, what a good samaritan letting us all know about your friends child. I hope you sell a lot of lenses.

      September 19, 2011 at 23:02 | Report abuse |
    • Des Welch

      Believe it or not, some people do actually care about others and want to spread the word about things that are good. The kid's name is Jared and he is from Chicago, because he is a minor, I can't share anything more than that. I don't have the doctor's name or any other information, if I were a salesperson I should be fired for not even giving basic contact info. Too bad so many people are so cynical and hateful.

      September 20, 2011 at 10:06 | Report abuse |
    • Anon

      So your friend told you all about the lenses and didn't even tell you the doctors name. Your friend is weird. Weird that your friend doesn't know how to post on CNN too. Weirder still that you so strongly recommend these lenses without even trying them yourself or on one of your family members.

      September 20, 2011 at 15:39 | Report abuse |
    • KT

      I am not familiar with the Chromagen system, but the blue or grey filters may have some potential scientific explanation. There are two neurological systems for carrying info to the brain. The magno and parvo systems. The theory is that the two systems are out of sync and that by filtering one system out, reading improves. I think this is reasonable sounding with my doctor of optometry background. And otherwise, I figure, if there are people who notice an improvement with filter use... then at the least there must me some placebo effect. Either way, seems win-win if you benefit. Of course, it won't help everyone and there are other problems that must be ruled out first or in addition.

      September 20, 2011 at 22:04 | Report abuse |
    • Eyes

      Thanks KT. This myth of magno and parvo cellular contributions to reading that you are describing has been well debunked. I would recommend you read the policy statement on learning and vision from the American Academy of Pediatrics. It's a shame that people try and take advantage of parents who's children are having reading problems.

      September 21, 2011 at 00:17 | Report abuse |
  3. Heinz M

    This is such an amazing pile of crock. Both my brother and myself have memories going back to the 6 month old and less than 1 year old stage. The times have been substantiated by certain acts that only took place at these times, and both of our vision memories are perfect. There was no blurriness of any kind at those ages.
    I always have to smile when I hear such 'scientific findings', that are pure conjecture, and essentially (mostly) unprovable.
    And in certain cases, like here, counter-able by people that by personal experience know better. I sure hope a government grant wasn't wasted on these 'findings'. Why not just takes some pages out of Grimm's fairy tales? 😉

    September 19, 2011 at 11:28 | Report abuse | Reply
    • No way

      No way in the world could you see or remember anything at 6 months of age. Don't kid yourself, you were probably 2 years old.

      September 19, 2011 at 12:17 | Report abuse |
    • 57 Types of Ignorance

      I always have to smile when I hear unverifiable anecdotal "evidence" being presented as superior to rigorous scientific research.

      September 19, 2011 at 12:26 | Report abuse |
    • Chartreuxe

      Conjecture. Look it up, Heinz.

      September 19, 2011 at 12:56 | Report abuse |
    • GSUA

      Heinz: Do you feel that those memories have retained the exact level of detail that they had when first formed? Ignoring the argument about memory formation at such a young age, I think it would be appropriate for you to at least concede that over time your adult brain could have rewritten what you remember seeing.

      September 19, 2011 at 13:09 | Report abuse |
    • JulieMS

      I'm sure it was probably from hearing someone mention these things you saw that sparked your memory.

      September 19, 2011 at 13:53 | Report abuse |
    • Will

      To the people who are doubting Heinz, I can tell you with 100% positive certainty that I had vision when I was born, because (a) I remember the plasticky texture of the mat I was on in the maternity ward, and (b) I remember the patterns on it (cartoon animals on a white background). I couldn't care less if people believe me or not, you aren't me and you don't share my memories so shut up. I have nothing to prove to anyone.

      September 19, 2011 at 18:04 | Report abuse |
    • Tom, Tom, the Piper's Son

      Yeah, you do. You're delusional and idiotic. That's the only proof I see here, you nitwit.

      September 19, 2011 at 21:18 | Report abuse |
    • Tom, Tom, the Piper's Son

      Heinz, you're nothing but a bottled tomato-brain.

      September 19, 2011 at 21:19 | Report abuse |
    • WasThere

      I too have vivid, detailed coroborated memories from about 6 months of age.. (I'm now 67) It did not seem significant before, but the visual imagery is sharp and clear and includes relatives who were living at the time but were deceased before I was two years old, so I could not have "remembered" them from later exposure.

      September 20, 2011 at 00:07 | Report abuse |
    • Tom, Tom, the Piper's Son

      Why not? Hadn't photography been invented? Come on. Anyone who watches TV knows that eye-witness accounts are unreliable.

      September 20, 2011 at 09:03 | Report abuse |
    • KT, OD

      A six month old sees much better than 20/600... that is a Newborn who sees that poorly. A six month old could see 20/60 or 20/80. Just a little bit larger detail than newspaper print. I also have memories from before age one. I remember yellow hall closet doors from a house we moved from by the time I was age one. And I remember wishing they'd let me look out the window longer before putting me in the crib.

      September 20, 2011 at 22:08 | Report abuse |
    • KT, OD

      The article did not define ages in months well. Color vision by four months. Depth perception by 6 months. These things are measurable. It is verifiable.

      September 20, 2011 at 22:16 | Report abuse |
  4. charls

    Vision is just like hearing and talking. A person "learns" to do all of these things. The difference is that hearing and talking are much more "visible" to the parents. Of course we have to learn how to see. We live in a three dimensional world but our vision presents the world in only two dimension, even with the help of binocular vision. When you are driving, you see a car coming towards you and you are able to make judgements about its size and motion based upon your experience seeing a moving car. Without that experience you would not be able to drive a car. This applies to the hundreds of activities that everyone does every day.

    This was a fascinating report and gives insight into a babies world.

    September 19, 2011 at 14:08 | Report abuse | Reply
  5. Bugs Bunny


    September 19, 2011 at 18:03 | Report abuse | Reply
    • Tom, Tom, the Piper's Son

      Sure thing, Cletus.

      September 19, 2011 at 21:20 | Report abuse |
  6. Tom, Tom, the Piper's Son


    September 19, 2011 at 21:22 | Report abuse | Reply
    • Christianna

      Tom, are you okay? Praying for you. I think you are going insane because you hate religion and support perv immorality and use filthy language. All of them are bad to your character and to your brain.

      September 20, 2011 at 01:20 | Report abuse |
    • Dan

      Really? Hating religion, having different morals, and using "filthy" language equals insanity to you?

      How about denying religion is sanity? Filthy language is a joke – what makes one word so much more offensive than another and who gets to decide? And perv immorality? That goes back to whatever cult you choose to follow I guess.

      September 20, 2011 at 08:58 | Report abuse |
    • mike3

      No, but when it seems that one is attacking people for not having a lot of intelligence - something they CAN'T HELP as it's what they were born with - then that looks really morally bad, at least to me. It's like attacking someone who was born without an arm for their lack of said arm.

      "How about denying religion is sanity?"

      So then are you saying NOT denying it is INsanity, and so a majority of the world's population is INsane and so *BAD* people? If so, then I really disagree. I'll side with the ones you call "idiot" on THIS particular issue, then. You can believe whatever the heck you please about religion - love it, hate it, whatever - but when you start calling others bad due to disagreeing beliefs about it, then you've got a problem (and this puts you in the same boat as a lot of religious people).

      September 20, 2011 at 15:18 | Report abuse |
    • Tom, Tom, the Piper's Son

      Just fine, dimbulb. You?

      If anyone is insane here, honey, it's you and your pals. Get your head examined, dufus.

      September 20, 2011 at 09:04 | Report abuse |
  7. Terry

    CNN, you forgot the degrees of the authors. They are Ph.D's. In this day and age anyone can claim anything. I researched the author's before I read the article. Excellent article though!

    September 20, 2011 at 06:06 | Report abuse | Reply

    I found it interesting that "During this period, babies also become better at distinguishing faces within their own racial group than within other racial groups, probably because most babies have more visual experience with their own group than with others"

    What about children with parents of a different race? (e.g. adopted )

    September 20, 2011 at 06:25 | Report abuse | Reply
  9. Des Welch

    Yes, some people do actually care about others and want to spread the word about things that are good. The kid's name is Jared and he is from Chicago, because he is a minor, I can't share anything more than that. I don't have the doctor's name or any other information, if I were a salesperson I should be fired for not even giving basic contact info. Too bad so many people are so cynical and hateful.

    September 20, 2011 at 09:47 | Report abuse | Reply
  10. ks31416

    I don't remember my vision as an infant, but I clearly remember that at 4 years my vision was sharp and in full color (much better than it is now). That makes the other grey and faint images at earlier ages also doubtful.

    September 20, 2011 at 13:42 | Report abuse | Reply
  11. Eyedoc

    Check out http://www.infantsee.com It is a program providing free eye exams for all children under 12 months of age. Well child exams can not pick up anything but very obvious vision issues, and the children are the ones that pay for the lack of referrals to eye doctors for comprehensive eye exams. We can learn the same information from an infant or other nonverbal individual as an adult, just using different techniques.

    September 20, 2011 at 13:48 | Report abuse | Reply
  12. mike3

    (that last post was a reply to "Dan", btw)

    September 20, 2011 at 15:18 | Report abuse | Reply
  13. 19steve19

    I remember being born. It was terrifying.

    September 20, 2011 at 15:42 | Report abuse | Reply
  14. SCamp13

    I am a tad hesitant to accept some details in the article, such as taking the example photos/timeline of how children may perceive faces.

    I say this because of both my experience with my own children (in which they frequently show signs of very much surpassing vision development "norms," and also my basic understanding of the development/role of the facial fusiform area of the brain. Though it is true that babies come to recognize aspects of human faces better over time, infants are actually initially much BETTER than older children and adults at deciphering even "monkey" faces with similar features – specifically 2 chimpanzee (can't remember if it was chimps or not) faces that to an adult would look essentially identical.

    It is only after some of that "learning" in the brain takes place that the infants lose that ability to detect differences in other species' faces and get more accustomed to/specialized for seeing human faces.

    Also, there are a lot of degrading comments on here (sheesh!). No need to beat others down because of their opinions or comments. Science is important and plays a role, but in no way is it complete, especially when it comes to the amazing depths of the brain's development. And though I respect PhD's a lot, I would lean more towards trusting the gut feeling of educated, up-to-date docs who can add to their scientific viewpoints a history of dealing with large numbers of the people such articles try to describe.

    Just my two bits.

    September 21, 2011 at 01:08 | Report abuse | Reply
  15. Sharp

    Interesting to see why people will say "Black people all look alike", or "White people all look alike." It makes sense if you are pre-programmed by only seeing members of your own race during this critical period.

    September 21, 2011 at 08:33 | Report abuse | Reply
  16. xyz

    Hi Sanjay,

    I have written in your forum a couple of times before. I saw your in Andersoncooper's show today for conjoint twins. Is this practical? How are the restroom habits? These two are girls, right? And you are a doctor...what about puberty? Will this work in the long run? The parents seem to be in good cheer, but I am surprised the parents wanted to continue with the pregnancy. I mean, with all the scans these days I am amazed a parent went through this. It is easy for me to suggest abortion, but this is quiet a strain on both of them. As the body matures and the weight of the body also increases....how will this work. How about their college education, married life !!!! What if one wants to do BA arts and the other Math, so is both the child going to take two degree courses? Why dont you suggest to the parents atleast behind the scenes about their married life? Is married life even possible?

    September 21, 2011 at 14:56 | Report abuse | Reply
  17. Allen

    you were meant to find it perhaps.You are celntiary on the right path and I know you are aware of it. You should not be surprised about being able to create your reality moment by moment e28093 for when we understand e2809cwhoe2809d we are and what we represent, then e28093 our imagination is the only limit.This appears to be in fact, the very point (I have seen a thousand times) preventing folks from understanding and realizing their full potential. We have been told (for thousands of years) that we are nothing more than a bunch of worthless sinners. It is so incarnated in our minds e28093 so imprinted in our dna that we find it very hard to believe and even more so to change our mindset e28093 realize that we are inside God e28093 not outside, God is then in us, we therefore are e2809ca parte2809d of God not apart from God.And this is where the e2809cbeing caught up with religione2809d comes is.You see Suzy; I do not have a single issue with religions, for I fully understand that it represents a sort of e2809clinke2809d, a stepping stone to the next level of understanding. I felt I had no choice stressing the issue so much in the book, simply because most folks seem to be so taken e28093 so terrorized even, by their present set of believes that it is almost impossible to have an intelligent conversation.Most people will simply state e2809c..But the bible sayse2809d. How can we base a conversation then e28093 on such a starting point?In my many interactions with people, I found it necessary to take the conversation one step at a time. Putting on the table clear e28093 possible examples of e2809chowe2809d did we get to the present status quo in the first place. A status quo we have accepted, as absolute truth, without caring where it came from. Again, all necessary and by design of course, for as a people we must go to kindergarten before we can attend high school and university.The first 3 parts in the book, (I agree) do stress the religion issue extensively. But that is in an effort to present it in as an easy fashion as possible. starting therefore from what most are familiar with, then attempting to introduce new possibilities.Suzy, I have talked to folks who are afraid to even mention the name of God. I have talked to folks who will not get on a plane because they believe they would be too undeservingly e2809cclosee2809d to Gode28099s place of residence.My job (as I understand it), is to make the information available. I wish Suzy I could have simply spelled it out the way it was given to me, or the way I comprehend it. If that was the case I would have been done with it 15 years ago. It would have only comprised of 30 very e2809ctechnicale2809d- way-out-there pages and that would have been it. I must keep in mind the audience it was meant for, I must spell it out in as simple to understand terminology e28093 most can relate to. To someone like you, it might appear as if it talks about very simple issues e28093 perhaps too extensively and too in detail. And so it does to me too Suzy. But you see the book was not meant for you and I, even though we can still use a e2809cremindere2809d once in a while.As you can understand, it can be a monumental task (especially so-when English is not your native language LOL) to translate the highest scientific, controversial, and so far reaching information, in a language that most un-researched folks can relate too.In a way, it feels sometimes as if I must be the one doing all of the research, then present it, while being fought every step of the way, with the only goal in mind to make better options available -there for anyone who might want to look at them.That is the biggest obstacle I have been faced with over and over throughout the years. The fact of being fought every step of the way, being accused even e28093 of trying and change someonee28099s believes, when in reality, all I was trying to do was to allow them to see that THEIR believe is so much more beautiful than they know, only if they allow themselves to see it.This is like someone driving their car in first gear all of their life, not knowing that more gears exist. Trying to explain to them, that what you trying to do is not to make them replace their car, but that the car they own has 4 more gears available, gears that if they learned to use, they would be able to travel much faster and more efficiently with.A very religious friend of mine whom I have known for 20 years, told me when we first started having these types of conversations back then that based on what I was trying to get across e28093 I was not e2809creligiouse2809d and that I did not believe in God. That was his comment 20 years ago.Today, having a clearer picture of what I have been trying to tell him all along, he tells me that I am infact 10 times more e2809creligiouse2809d and that I believe in God 100 times more than he does.In my friende28099s case, I have done my job. Which is really, to give folks the opportunity to see that we are NOT talking about e2809cchanginge2809d their believes e28093 but simply suggesting that there is a lot more about THEMSELVES that they normally give themselves credit for. An empowering message if you like, which puts us in an even better position to understand God, to honor the beauty and magnificence that God truly represents.Now, it is said that e2809canswers come to those who are readye2809d. Answers were given to you Suzy e28093 years ago already.If you allow me, I would suggest you spread the good news, whatever it is that you know you are here to share it.You have a lot of light and a lot of beauty in you e28093 that is meant to better others peoplee28099s lives.The reward is not having the knowledge itself, but to share it, so that others can find their inner light also.marco

    July 1, 2012 at 10:49 | Report abuse | Reply
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