I was at the birth of my nephew some years ago and the moment he came into the world is one that I will never forget. There was hardly a whimper. His mother gave birth with him on her hands and knees and he came out the back. As soon as his head emerged, I saw his eyes scanning the room, turning his head to see. It was as if he was saying, “So this is what it looks like out here!” My initial thought was, “He is a wise soul.”
I’ve always taken it for granted that a baby at the moment of birth will be able to open his eyes and just automatically see anything there. It never occurred to me to wonder how this actually happens. I believed that the optic nerve is developed in utero and then at birth it just starts working. Though this is true, it is not the whole story. How is it that a baby’s eyes are able to see at the moment of birth? Is it with the sudden stimulation of light? Or is there some preparation while in the womb?
Since then, I have learned more about the science of how a baby sees. The optic nerve doesn’t just automatically adjust to light on the outside – it has to have had preparation and practice while still in the womb. But how can this happen when it is dark inside the womb?
After about four months of gestation, the human fetus has grown 200 billion never cells in the brain, twice as many as it needs. 1 We do know that when nervous systems are not properly stimulated during specific critical sensitive periods in development, they never function properly, even if they are stimulated later.2 We also know that a fetus in the womb is exposed to sounds, pressure on the skin, smells and even flavors in the amniotic fluid. The fetal brain is actually shaped by these nerve signals that travel down nerve pathways. Those that are used most often become stronger. Those not used as often become weaker and may even be eliminated. So it makes sense that the optic nerve for sight would have a stronger pathway to prepare the infant to see at birth. But how?
The fetal brain uses artificial
stimulation to help its
visual system develop.
It was fascinating to read the answer to this question in “The Promise of Sleep” book by Dr. William Dement, MD. It turns out that neurological research provides evidence about another wonder of the human body. It has been discovered that the fetal brain uses artificial stimulation to help its visual system develop. He states, “Since the womb is dark, the eyes can’t send messages back to the visual area of the brain and give them the workout they need to develop. And yet, immediately after birth, the eyes and the visual areas of the brain work fine. This is possible because the eyes of fetuses create their own nerve signals, just as they would if activated by light. These signals then pass from the retina to the visual areas of the brain and give them the stimulation they need to form images later. This allows the visual system to organize itself so it can make meaningful images from the first patterns of light that hit the eyes after birth.”
“REM (Rapid Eye Movement) sleep continues to be an important part of visual development after birth, hitting brain cells in ways that complement the stimulation from light.”3 It is interesting to note that REM sleep is dream sleep so perhaps visual images in utero provide self-stimulation laying the foundation for its own organization by creating proto-sensations that train the brain and prepare it for the real-world sensations to follow.4 When the nerve cells for the visual system are not stimulated by either light or REM sleep signals, the visual nerve cells atrophied (wasted away) even faster. This suggests that REM sleep continues to be an important part of visual development after birth, exciting brain cells in a way that complements the stimulation from light.
At birth, babies cannot see very far, 8-15 inches but that is the perfect distance to see their mother’s faces. In fact, they prefer faces rather than other shapes, and also shapes that have light and dark borders – just like their mother’s eyes. A mother and her baby are primed to bond and connect with each other in fascinating ways such as this. They are several months old before they can see their first color – red.
What is important to know and believe, is that a baby at or near full gestation at the moment of birth is very competent. His nervous system is very well developed from the neck, up. The sucking reflex is primed for survival and is calming. No wonder then that the body since ancient times has determined a creative way for us to see at the moment of birth.
(See our blog on the size of baby’s eyes)
- Dement, William MD, PhD. The Promise of Sleep, Random House Inc, NY. 1999, pages 254.
- Ibid p. 254
- Ibid p. 254
- Ibid p. 254