The timetable, from two published sources

The AAP sets out infant vision in stages. At birth, a baby "can see light, shapes and faces" and "can also detect movement", but distance vision is "pretty blurry": "Your newborn can best see things that are about 8 to 12 inches (20 to 30 cm) away. This is roughly the distance from their eyes to yours as you are nursing or feeding your baby."

Then:

By 3 months: "Babies should be able to focus on faces and close objects. They should also be able to follow a moving object with their eyes."
By 4 months: babies "can use their vision to detect objects close to them, which they will often reach for and grasp", and are "now better at seeing colors and different shades of them".
By 6 months: a baby "should be able to see differences between objects and use this information to identify them".
1 to 2 years: the ability to see "will develop rapidly".
3 to 5 years: "a child with normal vision will typically see as well as an adult", and by ten "their visual system will be fully mature".

The HSE's eye health page gives the same arc with distances attached. Between six and eight weeks a child may "follow a coloured toy that is about 20cms (or 8 inches) away" and "move both eyes together". By about six months they may "see across a room" and "recognise familiar toys and people that are about 2 to 3 metres away". By about nine months they may "look at small things such as crumbs of bread that are 30cm (or 12 inches) in front of them" and "recognise familiar people who are across the room or street".

Wandering and crossing eyes

This is the commonest worry in the first months and it has a clear answer. The AAP: "It can take a little time for babies to learn how to use both eyes together. So, a newborn's eyes may occasionally 'wander,' cross or move randomly. This random movement should be going away by 2 to 3 months of age."

The NHS gives the matching cut-off for squints: get advice if "your child has a squint all the time", or if "your child is older than 3 months and has a squint that comes and goes – in babies younger than this, squints that come and go are common and are not usually a cause for concern".

The NHS also explains why it should not be left: "It's important not to ignore a squint that happens all the time or develops after 3 months of age", because untreated it can lead to a lazy eye, "where the brain starts to ignore signals coming from the affected eye, so your child does not develop normal eyesight".

Why early matters more here than almost anywhere else

Vision has a developmental window. The AAP puts it bluntly: after the visual system matures, "eye and vision problems that start early may no longer be able to be reversed or corrected. That's why early detection and treatment of eye problems in children is so important."

That is the reason eye checks are built into routine reviews from birth, and the reason a squint or a persistently different-looking eye is not something to keep an eye on for a few more months.

Signs of a problem to act on

The HSE lists, for younger children: a baby after six to eight weeks who "does not fix on and follow an object that is 1 to 3 metres away"; eyes "not looking in the same direction"; "not learning to respond to facial expressions – for example, not smiling"; "not reaching out to pick up objects"; "not noticing and following small objects"; being sensitive to light "even when it's not very bright"; rubbing their eyes; or eyes that "seem very large or prominent".

Those signs are worth checking deliberately rather than assuming you would notice. Look at your baby's eyes in good light, from in front, and watch whether both move together as you move slowly across their field of view. Photographs taken with flash are useful too, because they show the reflection in each pupil side by side.

A white or unusual reflection in the pupil, particularly in photographs where one eye shows red and the other does not, should be reported promptly rather than at the next review.

If your baby was born early

Use corrected age for the milestones above, and note that babies born very early are usually already under specific eye follow-up arranged by the neonatal team. The AAP advises adjusting for prematurity when tracking development until two years, and the HSE gives the arithmetic: a ten-month-old born two months early has a corrected age of eight months.

What helps

Very little needs buying. High-contrast patterns and toys are fine but not necessary; the highest-contrast, most interesting object in any room is a human face at arm's length, which is exactly where a newborn can focus. The HSE recommends getting face to face at "around arm's length", and adds bubbles as a way for older babies to practise "looking, tracking and waiting".

And do not skip the routine checks. Eyes are examined at the newborn examination, at the six to eight week check, and at later reviews, and those appointments are the main way problems get found before they matter.

Colour, and what babies actually prefer

Newborn colour vision is limited and improves through the first months. The AAP places better perception of colours and shades at around four months, and notes that babies of that age "may show extra interest in circular patterns like bull's-eyes and spirals", suggesting "this is one reason infants love to look at faces, full of round shapes and curves".

That is a more useful design brief than any product catalogue. A face at arm's length beats a black-and-white flashcard, because it moves, makes noise and responds. High-contrast toys are not wrong; they are simply not necessary.

Eyes that water

Watery eyes in a young baby are common and usually harmless. The NHS explains that "babies sometimes have watering eyes because their tear ducts have not fully developed", and that it "usually gets better by the time they're a few weeks old". Persistent watering, redness, swelling or discharge should be looked at, and any change in vision or severe eye pain needs urgent advice.

When Can Babies See Clearly