Once your baby is born, you’ll likely be dangling colourful toys in front of that tiny, cute face, showing your little one plenty of shapes and objects he will be seeing for the first time ever, and enticing your newborn to look at you (or the camera!) with wide eyes.
But long before birth — in fact, throughout most of your pregnancy — your baby’s eyes and brain are developing to prepare for those very stimuli. In fact, it takes more than six months of meticulous development in utero before your little one’s eyes are ready to process visual information from the outside world.
HOW THE EYES DEVELOP
Like other organs responsible for our five senses — the nose and ears, for instance — the eyes are controlled by the brain, which is connected through nerve cells. When a fetus is growing, one of the first parts of the visual system to start developing is the optic nerve, a thick bundle of millions of individual nerve cells that will pass information from the eyes to the brain and vice versa.
During week 4 of pregnancy, cells from the developing brain tissue begin to form two optic nerves, one on each side of the head. Around the same time, other cells start developing into what will eventually become the lens of the eye, which will help your baby focus on objects both near and far.
About a month later (around week 8 of pregnancy) the eye structure is even more complex and the retina — the layer of cells at the back of the eye that perceive and process light — has begun to form. By week 16, baby’s eyes have started to pick up on light and his eyes can make slight movements from side to side in response to it even though the eyelids still aren’t open.
When you hit week 26 (the end of the second trimester) your baby’s eyes are about as fully formed as they’ll get. Not only can those eyes sense light, baby’s eyelids can finally open. And your cutie will start to keep those eyes open and blink them when he’s awake. Though there’s not much to see in the womb, he’ll sense the movement of bright lights outside your body. Shine a flashlight on your growing belly from week 22 on and you just might get a kick or a wiggle in return.
HOW TO ENSURE YOUR BABY HAS GOOD EYESIGHT
In the past, researchers thought that eating a balanced diet during pregnancy was enough to encourage proper fetal eye development. Indeed, a number of studies have shown that certain nutrients are essential for eye formation — particularly vitamin A (found in leafy vegetables, some fruits and dairy products). Eating a variety of foods and regularly taking a prenatal vitamin helps ensure you get enough of all of those important nutrients.
Recently, though, scientists found something else that helps an unborn baby’s eyes: sunlight. Although it’s awfully dark inside the uterus, some photons of light still make it through your skin if you’re standing in the sun. And that little bit of sunshine, it turns out, is key to helping baby’s eyes develop. When pregnant mice are kept in complete darkness, their babies are more likely to have vision problems after birth. Similarly, data suggests that babies of women who live at northern latitudes and become pregnant during the darkest months of the year are at an increased risk of certain eye disorders.
Rest assured, though, you’re more than likely getting plenty of sunshine if you regularly spend time outdoors (or near a sun lamp in the dregs of winter) during your pregnancy. As always, be sure to follow the standard rules of sun safety to protect yourself from skin damage (that is, wear sunscreen if you’ll be outside for more than 15 minutes or so, apply 15 minutes before heading out, reapply every two hours, and try to stay in the shade between 10 a.m. and 2 p.m. — the hours when the sun is the brightest).
EYES AREN’T DONE DEVELOPING AT BIRTH
Unlike some parts of the body, your baby’s eyes will continue to mature even after he’s born — they have to adapt to the much brighter and busier world outside the womb, after all! So if your newborn has eyes that look crossed or can’t seem to focus on your face at first, don’t worry. Wait until baby’s around 6 months old to visit the optometrist to diagnose and treat crossed eyes or a lazy eye.
THE COLOR OF BABY’S EYES
What colour will your baby’s eyes be and how is eye colour determined? At the same time, your baby’s peepers are developing all the parts that allow him to see, he’s also building up cells that produce colourful pigments. Caucasian and other fairer-skinned babies are usually born with dark blue or even slate-grey eyes that may change several times before the first birthday, but African-American, Hispanic and Asian infants are almost always born with dark eyes that stay dark, though the shade may change slightly during the first year.
Remember, your baby’s eye colour is determined by genetics, but the pigment melanin, which is also responsible for the colour of your skin and hair, takes some time to build up after birth, including in the eyes. Just a smidge of it — like many Caucasian newborns have — makes eyes look blue. But add some more and you get green, grey or hazel; even more and your baby’s eyes will be brown or black.
The most dramatic changes to eye colour usually occur when your child is between the ages of 6 and 9 months old. By that point, the iris has stashed enough pigment so you’ll be able to better predict what the final hue will be. No matter what colour baby’s eyes are in the end, one thing is certain: You won’t ever get sick of looking into them!