Once your baby is born, you’ll likely be dangling colorful toys in front of that tiny 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.

When do babies open their eyes? 

Even before he’s born, your baby can open his eyes in the womb. He’ll first be able to open his eyes in utero around week 27 of pregnancy (the end of the second trimester).

Your baby will also begin to blink months before birth. Around the beginning of the third trimester (week 28), your baby will begin to keep his eyes open and blink them when he's awake.

Your baby’s eyesight development

Like other organs responsible for our five senses — the nose and ears, for instance — the eyes feed information to the brain, which is connected through nerve cells. 

During week 4 of pregnancy, cells from the developing brain tissue begin to form two optic nerves, one on each side of the head. These thick bundles of millions of individual nerve fibers will pass information from the eyes to the brain and vice versa.

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. The retina — the layer of cells at the back of the eye that perceive and process light — has begun to form. 

By week 16, your baby’s eyesight development has advanced to the point where he can start to pick up on light. His eyes can make slight movements from side to side in response to it, even though the eyelids still aren't open. 

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. 

By about week 28, your baby’s eyes can sense light, open and even blink when he’s awake.

How to ensure your baby has good eyesight

Eating a balanced diet during pregnancy encourages proper baby eyesight development. Certain nutrients are essential for eye formation — particularly vitamin A (found in fish, meat, dairy, kale, spinach, carrots and sweet potatoes, among other foods). Eating a varied diet and taking a prenatal vitamin helps ensure you get enough of this and other important nutrients.

Sunlight may also help an unborn baby’s eyesight development, some research has found. 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. 

Rest assured, 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 pregnancy. As always, follow the standard rules of sun safety and use a pregnancy-safe sunscreen to protect yourself from skin damage.

Do eyes grow?

Your baby’s eyes will continue to grow after birth — a lot! A newborn’s eyes are about 16.5 millimeters in length, while an adult’s eyes measure in at around 24 millimeters. Significant eye growth occurs during the first two years of life, although eye growth picks up again (along with the rest of your child’s body) around puberty. 

Your baby’s eye color may also change all the way up until he’s 3 years old as well as his eyesight as he adapts to the much brighter and busier world outside the womb. 

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 your baby’s around 6 months old to visit an eye doctor to diagnose and treat crossed eyes or a lazy eye.