Eye checks for a child with autism or ADHD
Parents arrive apologising for a child who will not sit still, expecting to be turned away. Almost everything I need to measure can be measured anyway, in a different order and over a little more time.
- A child does not need to read, speak or cooperate for their focus and eye alignment to be measured accurately.
- A squint is roughly four to five times more common in autistic people, and one large national study found higher rates of long sight, short sight and astigmatism too.
- In ADHD, astigmatism, long sight and squint turn up more often, along with focusing and convergence difficulty, but the retina itself is no different.
- None of these studies says autism or ADHD causes eye problems, and glasses will not change either diagnosis. They remove one avoidable obstacle.
- Tell the clinic when you book, ask for the quietest slot, bring the headphones and the comfort object, and plan for two visits rather than one.
The sentence I hear most often at the start of these appointments is an apology. "Sorry doctor, he won't sit still." It usually arrives before the child is properly through the door, from a mum who has already had a hard morning getting here and is braced for me to say that we cannot do this today.
We nearly always can. An eye examination is not one test a child either passes or refuses. It is a stack of separate measurements, and most of them ask nothing of the child at all. What changes for an autistic child, or a child with ADHD, is the order I work in and how long I take.
Can my child be tested at all if he will not sit still or speak?
Yes. The NHS puts it in one plain line I wish every parent heard early: children can have an eyesight test at any age, and they do not need to be able to read, or even speak. Naming letters is the only part of an eye examination that needs words, and it is the part I can most easily replace.
Everything else is watching. I see how each eye takes up a target and holds it. I move something interesting through eight different positions and watch whether both eyes travel with it. I look at the reflection of a small light on each cornea to see whether the eyes are aimed at the same place. None of that needs an answer, a promise to sit still, or a second of eye contact with me. It needs a child in the room and a target worth looking at, quite often your own phone playing something they already love.
A child who will not speak to a stranger can point at a matching card on their lap instead of naming anything. How we measure the sight of a child who cannot read goes through those games in order, and it is worth reading before you come.
Do autistic children really have more eye problems?
More often, yes, and this is why I want to see them rather than assume the difficulty is behavioural. A systematic review that pooled forty six studies found a squint, what we call strabismus, roughly four to five times more common in autistic people than in people who are not autistic. A separate national study followed nearly twenty one thousand autistic children in Taiwan against more than two million other children and found higher rates of long-sightedness, short-sightedness, astigmatism and squint, with squint about twice as likely.
The same review found differences in how the eyes work rather than how they are built: more difficulty with focusing, with depth perception, with contrast, and with telling colours apart. Those go unnoticed for years, because a child who has always seen this way has nothing to compare it with.
One thing those studies do not say, and I want to be careful here, is that autism causes eye problems or that eye problems cause autism. Every one of them states plainly that the relationship, if there is one, is not understood. What they establish is simpler and more useful to you: these findings turn up more often, so they are worth looking for.
Could my child's ADHD have something to do with his eyes?
Not as an explanation, but often as a passenger. In children with ADHD the pattern is a little different from autism, and the detail matters. A review pooling thirty five studies and more than three million participants found astigmatism, long-sightedness and squint each roughly twice as common, and found a much bigger difference in how close the eyes can comfortably converge on something near.
The same review found no difference at all in the retina itself, and no difference in refractive error measured as a continuous quantity. So this is not a different eye. It is an eye that is more likely to be working hard to hold near focus, and more likely to be doing so in a child who already finds sitting with a book difficult. That combination is worth untangling, which is what the homework headache that turns out to be an eye problem is about.
I say that plainly, because hope in the waiting room runs ahead of the evidence. Nobody should be told that glasses will settle their child's attention. What glasses do is stop a child straining to keep the page clear on top of everything else.
What can actually be measured if my child answers nothing?
The two things that matter most. The first is how each eye focuses, measured with a streak of light and a set of lenses held in front of the eye. The answer comes off the back of the eye, not out of the child's mouth. The second is alignment, read from the light reflection and from what each eye does when the other is covered.
Beyond those, I can look at the lids, the surface, the pupils and, with the pupil opened, the whole inside of the eye. A child who lets me do that in three short goes has still had a complete examination. What I may not get on the first visit is a precise sharpness figure for each eye on its own, since that is the one measurement that needs cooperation. That is a reason to come back, not a reason to stay away.
Will they force the drops in?
No. Nobody in my clinic holds a child down to put drops in their eyes. But I want to be honest about the drops, because for many children this is the hardest part of the visit and a surprise makes it worse.
Dilating drops do two jobs. They open the pupil so I can see the back of the eye through it, and they relax the focusing muscle, which is the best way to measure a child for glasses. They sting for a few seconds. After that, near vision is blurry for somewhere between four and twenty four hours and bright light feels harsh, so a hat or sunglasses for the trip home is a kindness. Unequal pupils afterwards look alarming and are usually one eye taking the drop better than the other.
Tell us in advance if drops are likely to be the sticking point. Getting a drop into a small human has the practical techniques, and for a child with strong sensory reactions the useful ones are the ones that avoid a struggle: lying down with eyes closed, the drop into the inner corner, and no countdown.
How do I prepare her for the appointment?
By making the room boring before she gets there. Tell the clinic when you book that your child is autistic or has ADHD, and ask for the first slot of the session or the last, when the waiting room is quietest.
- Bring the headphones, the chew, the tablet, the toy she uses to regulate, whatever it is. Nothing on that list interferes with the examination.
- Show her a photo of the machines beforehand if pictures help, and use the same words the clinic will use.
- Warn her about the two hard bits specifically: the bright light, and the drops that sting for a moment.
- Feed her first. A hungry child at four in the afternoon is a different child.
- Plan for two visits and be pleasantly surprised by one.
You can also stop the moment it stops being useful. A child who leaves upset fights the next appointment, and I would rather have three calm short visits than one nobody wants to repeat.
Do we need a special clinic, or is the ordinary one fine?
The ordinary one is usually fine, as long as it is a clinic that sees children and you have told them what to expect. What your child needs is a full examination with drops and a look at the back of the eye, and that is the same examination every child gets. A known squint, a suspected lazy eye or a puzzling result gets sent on to a paediatric eye service in the normal way, which is how a lazy eye is picked up in any child.
In the government system the route is the same as for anyone else, a referral letter written by a doctor, government or private, and what actually happens at a government hospital eye clinic is worth reading first. Say on the phone that your child is autistic or has ADHD and ask for a quiet slot. Most clinics will try.
The difficult appointment you are imagining is usually not the one you get. Your child is not too difficult to examine. They are examined in a different order, over a little more time, and the measurements that matter most never needed their permission in the first place.
- One eye turns in or out, constantly or only when your child is tired.
- Your child objects strongly when one particular eye is covered but not the other.
- There is a white, pale or glowing pupil in a photo or in ordinary light.
- Your child holds books or a screen unusually close, tilts their head, or closes one eye to look at something.
- Reading or close work brings on headaches, or your child pushes the page away after a few minutes.
Common questions
My son is autistic and will not sit for an eye test. Can they still check him?
Do autistic children have more eye problems?
He was diagnosed with ADHD. Could his eyes be part of the reading trouble?
Will they force the drops in?
How do I prepare her for the appointment?
Do we need a special clinic or is the normal one fine?
Can they measure her sight if she will not say anything at all?
- Association between Autism Spectrum Disorder (ASD) and vision problems. A systematic review and meta-analysis, Molecular Psychiatry 2023 · pubmed.ncbi.nlm.nih.gov
- Higher risks of hyperopia, myopia, astigmatism and strabismus in children with autism spectrum disorder: a nationwide, population-based cohort study, Brazilian Journal of Psychiatry 2025 · pubmed.ncbi.nlm.nih.gov
- Association between ADHD and vision problems. A systematic review and meta-analysis, Molecular Psychiatry 2023 · pubmed.ncbi.nlm.nih.gov
- NHS · Eye tests for children · www.nhs.uk
- AAPOS · Dilating eye drops · aapos.org