I had a squint as a child. Will my baby have one?
You had a squint (mata juling) as a child, and now you are watching your baby's eyes. What the studies show about inheritance, in plain numbers, what to ask Ah Ma and Atuk, and what to do next.
- A family history makes a squint more likely. A review of 41 studies found a strong hereditary link, particularly in intermittent and accommodative forms, but no test can tell you if your baby will squint.
- In one small study, 26.1 percent of first-degree relatives of children with accommodative esotropia had a squint, against 14.9 percent for infantile esotropia. That counts relatives of children who already squinted, not the chance for your baby.
- Find out which kind of squint the family had: which eye, in or out, always or sometimes, what age, and whether glasses, a patch or an operation followed. Write it in the child health book.
- In babies under 3 months, a squint that comes and goes is common. The NHS says to get advice for a squint that is there all the time, or one that comes and goes after 3 months.
- A normal look at birth does not rule out a squint later. Mention the family history at routine visits, and act early if your baby's eyes look misaligned.
You are holding your baby, and somewhere in the back of your mind is the photo of you at six, with one eye drifting inward. Ah Ma remembers the patch. Atuk remembers the operation. The question is whether the squint (mata juling, where the eyes point in different directions) has been passed on.
The honest answer is: more likely, not certain, and the way to handle it is to know what to watch for and to say so early. This page sets out what the studies show, in plain numbers, without frightening you.
If I had a squint as a child, is my baby more likely to have one?
Yes, more likely, though not certain. A systematic review in JAMA Ophthalmology, which reviewed 41 studies, found that inheritance is among the recognised risk factors for the common kind of squint, and that a strong hereditary link is present, particularly in the intermittent (comes and goes) and accommodative (linked to long-sightedness) forms. The NHS says the same in one line: sometimes squints run in families.
Two things keep this in proportion. First, the inheritance pattern is complicated. The review says twin and pedigree studies support inheritance but reveal a complex pattern, and only one gene location has so far been supported, with others reported. So no test can tell you today whether your baby will squint. Second, "more likely" is not "will". In the small study below, most relatives were not affected.
What do the numbers actually say?
The best available figures come from a small study, which needs careful reading. Researchers in Leicester, England, interviewed the parents of 96 children who were attending for squint treatment and drew up three-generation family trees. They then counted how many first-degree relatives (parents, brothers and sisters) had a squint.
Among relatives of children with accommodative esotropia (an inward turn linked to long-sightedness), 43 of 165 first-degree relatives, or 26.1 percent, were affected. For infantile esotropia (an inward turn from early infancy) it was 15 of 101, or 14.9 percent. For anisometropic esotropia (an inward turn where one eye needs a much stronger lens than the other) it was 8 of 66, or 12.1 percent. For exotropia (an outward turn) it was 1 of 25, or 4 percent, though only six children were in that group, so it cannot settle the question for exotropia.
Read that with care. It counts relatives of children who already had a squint, and it does not tell you the chance that your baby will squint. The groups are small, the study came from a single centre, and the authors themselves say the role of heredity in accommodative esotropia needs more investigation. What it does show is that a family history is more common in some types of squint than in others, so the type in your family matters.
Does it matter which kind of squint the family had?
Yes, and it is the most useful thing you can find out. A squint that turns inward and was treated with glasses points to long-sightedness. One that drifted out only when someone was tired or daydreaming, and vanished on other days, points to an intermittent kind, described in the squint that comes and goes. Both were the forms the review linked most strongly with inheritance.
Ask the relatives who were there. Which eye? Did it turn in or out? Was it all the time or only now and then? At what age was it noticed? Did the child wear glasses, a patch, or have an operation? Write down the answers, with dates, in the child health book. If you already have one child in glasses, what about the second covers what to do about the next child, since long-sightedness and squint are close cousins.
Not every squint is inherited. The NHS says a squint in a child is often the eye trying to overcome a vision problem such as short-sightedness, long-sightedness or astigmatism. The 2013 review lists other risk factors: low birth weight, prematurity, scarring retinopathy of prematurity, and a big difference in glasses power between the two eyes. Most squints are not caused by anything a parent did or did not do.
What should I watch for in my baby's first months?
An eye that turns in, out, up or down, all the time or in bursts. The NHS says to get advice if a child has a squint all the time, or if a squint that comes and goes is still there after 3 months of age. In babies younger than that, squints that come and go are common and not usually a worry. The AAO says that strabismus in children under four months sometimes resolves without treatment, particularly if it is intermittent or variable.
Two more things to hold onto. A wide, flat nose bridge can make a baby's eyes look crossed when they are straight, which is why pseudostrabismus is worth reading about. And a squint can develop later, since, as the NHS puts it, some people are born with one and others develop one later. So a normal look at birth does not rule out a squint next year.
The page on crossed eyes in newborns shows what a normal wandering eye looks like in the early weeks. A turn that appears suddenly in an older baby or toddler is a different matter: see sudden squint in a toddler.
When should I mention the family history, and when should my baby be checked?
Mention it at the first routine visit, and again whenever you are worried. The sources checked for this page give no fixed age for an eye examination in babies with a family history, so none is given here. What the NHS does say is that a GP, health visitor or local optician service can refer a child to an eye specialist for tests, so start where you already go.
In Malaysia that could be a child health visit at the klinik kesihatan, where the entries in the child health record book are a natural place to note "squint in mother as a child". Our page on the baby's first eye check explains what a first check involves. Do not wait to be asked. A family history is useful information for the examiner.
What if my baby does turn out to have a squint?
Then it is found, and there are steps to take. The NHS says treatment is usually recommended, because a squint is unlikely to get better on its own and could cause further problems if not treated early. The treatments include glasses (if the squint is caused by a vision problem), eye exercises, surgery on the muscles that move the eye, and, for a lazy eye, a patch over the better eye.
The reason for the hurry is the lazy eye (amblyopia, where the brain starts to ignore the signal from the eye that is misaligned). AAPOS explains that when the eyes look in different directions, the brain receives two different pictures and may ignore the picture from the misaligned eye, so that eye's vision does not develop as it should. Our article on how to spot the drift covers the signs. If an operation is suggested, squint surgery, what happens on the day describes it.
The NHS adds that surgery can help improve alignment even when a squint has been left for a long time, but vision problems may be permanent if they are not treated at a young age. That is why the family history is a reason to look early, and not a reason for guilt.
What if my own eyes have changed as an adult?
A squint in adults has its own causes, and a new one is a reason to see your own doctor. The NHS says to get advice if you develop a squint or double vision later in life. AAPOS lists stroke or vascular problems, trauma, neurological problems and thyroid eye disease as common causes in adults. On another site, an oculoplastic surgeon explains when double vision in an adult is caused by thyroid eye disease or an orbital problem rather than a straightforward squint.
For most parents, though, the question is simpler. You had a squint, you told the doctor, and you are watching your baby's eyes with an informed eye.
- Has an eye that turns in, out, up or down all the time, at any age.
- Still has a squint that comes and goes after 3 months of age.
- Has an eye that suddenly turns after months of looking straight. See the article on sudden squint in a toddler.
- Turns the head to one side or keeps one eye closed when looking at things, which the NHS lists as signs of a problem.
- Has a squint that seems worse or more frequent over days or weeks.
Common questions
Is squint hereditary?
If I had a squint, will my baby have one?
Is lazy eye genetic?
Which kind of squint is more likely to run in families?
When should a baby with a family history of squint have an eye check?
Can my baby's eyes look crossed and still be normal?
What is the treatment for squint in a baby or child?
- JAMA Ophthalmology 2013 · Risk factors and genetics in common comitant strabismus: a systematic review of the literature · pubmed.ncbi.nlm.nih.gov
- Eye 2002 · A study of heredity as a risk factor in strabismus · pubmed.ncbi.nlm.nih.gov
- American Academy of Ophthalmology · Esotropia and Exotropia Preferred Practice Pattern (2022), highlighted findings · www.aao.org
- AAPOS · Strabismus (glossary entry) · aapos.org
- NHS · Squint · www.nhs.uk