If you’re a new parent, you might be wondering if your baby can see you making silly faces across the room or whether their crossed eyes are normal. Infant vision matures rapidly from birth and is essential for babies to reach normal developmental milestones. It can be difficult to determine what eye changes are normal or abnormal in infants. We’ll review some of those differences in this article.
What eye changes occur during infancy?
The visual system is immature at birth and progresses within the first few years of life. This feature is different from other senses, such as hearing (which is fully developed in newborns).
The critical period is the time in a child’s life when brain cell connections are more plastic (able to change and strengthen). If the brain doesn’t receive proper sensory input during this time, skills such as hearing and seeing may not develop normally. This hardwiring of the brain becomes much harder to change as a child grows older.
The critical period varies for different visual skills:
- Visual acuity (clear, detailed vision) develops from birth to age 5. Visual acuity of 20/20 corresponds to normal adult vision, while 20/200 means you can only see the large letter at the top of an eye chart.
- Stereopsis (depth perception) develops from 5 months to age 2.
- Color vision develops primarily from birth to 5 months.
- Amblyopia (lazy eye) is abnormal visual development from poor vision in one eye or strabismus (eye turn). Amblyopia can develop at several months of age up to age 8.
What visual developmental milestones should I expect in my baby?
The following are eye-related findings that occur within the first year of life.
- Visual acuity is 20/400 (primarily focusing on objects 8 to 10 inches away)
- Can fixate on objects
- Cannot follow objects easily
- Intermittent strabismus may occur (eyes may occasionally wander or appear cross-eyed)
1 to 3 months:
- Visual acuity improves from 20/300 to 20/100
- Focuses on parents’ faces and makes eye contact
- Eyes develop normal alignment
- Can follow moving objects and reach for them by 3 months
- Binocularity is detectable (both eyes track together)
3 to 6 months:
- Visual acuity improves from 20/100 to 20/30
- Eyes appear straight, and no eye turn is present by 5 months
- Eye movement and coordination continue to improve
- Watches their own hands
- Grasps and holds objects, may place them in the mouth
- Eyes move from person to person or between objects
- Depth perception begins around 5 months
- Color vision is mostly developed around 5 months
6 to 9 months:
- Eyes can track objects at near and far (greater than 6 feet)
- Purposefully reaches for objects
- Crawling around 8 months helps to develop eye-body coordination
9 to 12 months:
- Recognizes the faces of parents or other family members
- Looks at small objects such as cereal
- Can judge distances and throw objects with more precision
- Pulls themselves up to standing around 9 months
- Most babies try to walk by 12 months
Monitoring these milestones helps ensure your baby's development is on track. However, knowing what's abnormal and when to seek medical help is equally important.
What are some signs of eye problems in infants?
It’s critical to monitor your baby closely to ensure they don’t develop issues that may be complicated to treat if the diagnosis is delayed or have permanent effects on their vision.
Some signs to look for include:
- Strabismus may occur intermittently at birth. In most cases, the eyes align within a few months. A constant eye turn is cause for concern and should be addressed promptly to reduce the risk for amblyopia.
- Droopy eyelids can be present at birth. If the eyelid blocks the child’s vision, amblyopia can develop.
- Epicanthal folds are upper eyelid skin folds covering the inner corner of the eye. These folds are not concerning and are common in babies of Asian descent. However, epicanthal folds can cause the eyes to appear crossed when they are straight. Excessive tearing can indicate blocked tear ducts or congenital glaucoma. Glaucoma in babies requires prompt treatment to lower eye pressure.
- Light sensitivity and tendency to shut the eyes are also suggestive of congenital glaucoma.
- Clouding of the eye can indicate congenital glaucoma, cataracts, or corneal scarring. These conditions can affect visual development.
- Red eyes with discharge or crusting may indicate an eye infection or a blocked tear duct.
- White pupils are a sign of a rare but aggressive eye cancer called retinoblastoma. These tumors can grow rapidly and spread to other areas of the body, so prompt medical attention is required.
If you notice any of the signs above in your baby, consult a pediatrician or eye specialist immediately. Early detection and treatment of eye disease can save vision or, in cases of retinoblastoma, save an infant’s life.
Block, Sandra, et al. (2018). 18 Vision Development Milestones From Birth to Baby’s First Birthday. Prevent Blindness. https://preventblindness.org/wp-content/uploads/2020/04/18_Key_vision_questions.pdf
Hyvärinen Lea, et al. (2014). Current Understanding of What Infants See. Curr Ophthalmol Rep. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4243010/
Mills, Monte D. (September 1, 1999). The Eye in Childhood. American Family Physician. https://www.aafp.org/pubs/afp/issues/1999/0901/p907.html