Most parents of infants know that during the early weeks of life, babies can only see bold, high-contrast items at close range. (It's no coincidence that so many infant toys have graphic, black-and-white patterns.)
So when can babies start to distinguish color?
"Based on special studies looking at babies' preferences in response to various color stimuli, it is believed that babies can distinguish colors as early as three to four months," says Riley Children’s Health ophthalmologist Dr. Charline Boente.
In a study described in Scientific American, researchers in Japan monitored the brain activity of babies as they looked at geometric shapes of different colors, and found it to be similar to that of adults they also tracked. When the color switched (say from red to blue), they saw increased activity in the area of the brain that processes visual stimuli. When it remained constant (for example, a lighter green to a darker green), the activity level was steady.
When do I know if my baby is color blind?
That takes a while, said Boente. "As you can imagine, it’s difficult to accurately test when babies are able to distinguish colors. Until kids can communicate what colors they are identifying, it may be difficult to even know that a child cannot distinguish or even see colors, since the child perceives this as their normal," she said.
What vision-related milestones need to come before seeing colors?
Boente says that there are many "anatomical and physiological factors" involved in a baby's developing visual system. "Babies must have the ability to identify and focus on objects before seeing colors, and in particular, normal development of the optic nerve and retina is very important," she says.
How do I stimulate my child's visual development?
Know that you don't need to buy any special flashcards or gadgets. "It's important for parents to encourage their child to use their vision by simply interacting with them," says Boente. To stimulate cognitive development, the American Academy of Pediatrics recommends activities like taking a walk and pointing out unfamiliar objects, having fun imitating your baby's facial expressions or looking at books together, which encourages interaction.
Babies especially love books that show faces, and there's science behind this: A study at Stanford University shows that unlike with basic objects, babies can process human faces using adult-like levels of brain activity, and may develop face-recognition skills earlier.
Does my baby need an eye doctor yet?
According to Boente, "Your child's pediatrician can evaluate age-appropriate vision milestones," and the American Academy of Pediatrics recommends the following eye exam schedule for babies. (If concerns are spotted, your doctor will refer you to a pediatric ophthalmologist.)
Newborn: Before going home from the hospital, babies should be screened for eye issues like glaucoma or infections.
By age 6 months: Pediatricians should check things like vision development and alignment during well visits..
Age 1 to 2 years: A physician may use a photoscreening device, which has a camera and flash to look for problems like amblyopia (sometimes called "lazy eye," it refers to issues where the brain and eyes aren't working together properly).
Age 3 and up: Vision should be checked annually, with separate eye checks starting at 5.
What warning signs should parents watch for during a baby's first year?
"The main way we measure vision in the first year of life is by observing the baby's tracking behavior," says Boente, adding, "In a healthy full-term infant, by two to three months of age he or she should be able to track objects and respond to familiar faces and objects."
Along with tracking, she also suggests that parents let their pediatrician know if they encounter any of the following symptoms:
Overall visual disinterest
Eyes crossing inwards or outwards (after four months, since before that, some misalignment may be normal)
Nystagmus, meaning eyes move quickly and uncontrollably either vertically, horizontally or in a circular motion