Vision development. What to expect during the first year of life?
The vision of a baby runs through several crucial stages, with exponential development happening during the first year of life. The harmony of relationship between structure and function is very important for a proper visual system’s structuring. This is the reason for cooperation and complementarity between Paediatric, Family Doctor and Paediatric Ophthalmologist in evaluating a baby during child health follow-up appointments. Knowing always what is happening during a child’s growth may help parents to detect and prevent eventual specific needs.
Birth: a discovery
At birth, newborns are very sensitive to light. One can perceive it by the small size of pupils, which limits the amount of light entering their eyes. Vision is significantly poor during this period, with very rudimentary reactions to visual stimuli such as slow eye and head movements towards a stimulus direction. Therefore, newborns can use peripheral vision to see something next to them – which helps them to define the general outline of a face -, but their central vision is not yet developed. Motion sensitivity is a universal characteristic of all vision systems, thus being one of the first developing functions; this explains why newborns prefer moving elements, especially the ones close to them (due to their still low visual acuity).
From two to four months: focusing and tracking
For the first two months, the eyes of a baby may seem like lacking motor coordination, especially when noticing the rhythm of their lateralisations to follow an interesting stimulus. That is normal in most cases and usually fades away during growing process. Nevertheless, such characteristic is different from a constant eye deviation, known as strabismus. Real strabismus or visual axes misalignment is not normal and barely fades away, unlikely the very common pseudo-strabismus – subjective notion of an imaginary misalignment -.
For this reason, with about two months of age, babies can generally follow a moving object as their visual coordination improves. In fact, with 3 months of age, your baby may already have enough eye and arm coordination to intercept a nearby moving object. For making it happen eyes must work together to focus and track objects. This is called binocularity.
Chromatic, absent or poor vision in the first month of life develops during the second month with the first discrimination of red-green axis and then blue axis (around 3 months of age), with a global improvement happening until the end of the first year. Therefore, by being progressively able to integrate different object characteristics, such as color, orientation and movement, which are associated to an improvement of attention and central vision, babies then start intentionally communicating, socialising, understanding and interacting with the world around them.
From five to eight months: reaching, recognising and recalling
Around five months of age, the baby’s ability to see how far an object is from them (called depth perception) has increased: they can now see the world in three dimensions and that is clear as they improve their ability to reach both far and near objects. At the same time, they are able to segment a place, discriminating its surrounding object which means they are arousing reflex or intentional interest towards a new stimulus.
In this stage, a baby may recognise their parents across a room and smile to them: they can even recall an object, even if they can only see a part of it.
Usually they start crawling around eight months of age and improve their eye-hand coordination.
From nine to twelve months: grasping, grabbing and on the go
With about nine months of age, babies generally judge distance very well. This is the time when they start standing up. By ten months of age, with visual acuity, discriminative and depth ability improvements, they can grab something between their thumb and forefinger. Object manipulation becomes more refined. With twelve months, most babies are crawling and trying to walk.
Source: American Academy of Ophthalmology – https://www.aao.org/eye-health/tips-prevention-list