Cigarette smoke, vapes and a child's eyes: at home, in the car and the teenager who vapes

It is a question parents often ask quietly: my husband smokes on the balcony, or my son vapes in his room, is that why her eyes are always red? Behind it there is usually a good deal of worry, and some blame, already.

I am not here to add to it. This page sorts what the research shows reliably from what is only a link, and ends with the changes that matter first. If the red eyes come with a hazy sky rather than a smoker, haze days and little red eyes is the page you want.

Does cigarette smoke at home or in the car really affect my child's eyes?

Yes, for the eyes' surface: stinging, redness and dry-eye symptoms. A 2023 systematic review in Survey of Ophthalmology, which pulled together 55 studies, found compelling correlational evidence that second-hand smoke goes with eye irritation, conjunctivitis and dry-eye symptoms. For almost every other eye condition it found the evidence limited or controversial.

That split is the honest shape of this subject. The surface effects are well supported. The deeper claims, about short-sightedness or a child's eye development, are not settled, and I will say which is which below. Smoke matters for the rest of the body too: the US Centers for Disease Control and Prevention (CDC) states there is no safe level of exposure to second-hand smoke, and that children exposed to it have more respiratory infections, more ear infections and more frequent and severe asthma.

Why do my child's eyes sting, water and go red around smoke?

Because smoke lands on the tear film, the thin wet layer that covers the front of the eye, and unsettles it. An updated review in Experimental Eye Research, covering active smoking, passive smoking and e-cigarettes, concluded that most of the reported work shows cigarette smoke reduces the stability and quality of the tear film. A tear film that breaks up quickly gives you the gritty, watering, stinging eye.

It looks like the haze picture, and it is handled the same way: out of the smoke, cool damp cloth, plain lubricating drops, no rubbing. Why children rub their eyes explains the rubbing loop, and dry, gritty eyes in a hot spell covers the dry-eye side. If your child's eyes are already itchy and allergic, the itch that never goes away is where to start.

Does second-hand smoke make short-sightedness more likely?

Possibly, but nobody can tell you so today. A 2026 meta-analysis of 11 studies of postnatal passive smoking and myopia found no overall association (odds ratio 1.00, 95% confidence interval 0.82 to 1.20). The studies that followed children over time did show one, with an odds ratio of 2.13, while the cross-sectional studies did not. Exposure was mostly reported by parents, and the studies did not consistently account for outdoor time, near work or short-sighted parents.

The authors call the cohort finding hypothesis-generating, and I agree. Please do not read this as "smoke causes short-sightedness". The things with a firmer evidence base are on other pages: short-sighted parents, time outdoors, and an eye check if a child squints at the board.

Does smoking in pregnancy affect a baby's eyes?

It is linked to squint, and the link is consistent. A 2019 meta-analysis of 11 studies covering 4,833 children with strabismus found maternal smoking in pregnancy was associated with squint in the child (odds ratio 1.46, 95% confidence interval 1.32 to 1.60), and 10 or more cigarettes a day gave a higher figure (1.79) than fewer than 10 (1.17). A 2025 genetic study in Nature Communications used a method called Mendelian randomisation and reported genetic evidence supporting maternal smoking as a causal risk factor.

Two things keep this in proportion. A squint has many causes, genetic and environmental, so smoking is one thing that shifts the odds and never the explanation for one child. And a baby who already has a squint needs the same thing any child does: a proper eye examination, covered in squint and lazy eye, a parents' guide.

If you smoked before you knew you were pregnant, or could not stop, please do not carry that guilt into the clinic. The useful moment is now, and stopping now still protects the child in front of you.

Does smoking on the balcony or opening the window protect my child?

Less than parents hope. The CDC states that completely eliminating smoking is the only way to fully protect people who do not smoke, and notes that most people are exposed to second-hand smoke at home or at work. I cannot give you a number for a balcony or a car with the window down; no study measures one.

A sensible order is a sequence rather than a rule. First, no smoking in the car, which is a small closed space the child cannot leave. Second, none indoors. Third, if a smoker steps outside, further from the door and the window than feels necessary. None of these is a promise. Each is a smaller dose for a small body.

If your child has asthma, the case for the car rule is stronger still: the CDC states second-hand smoke can trigger an asthma attack in a child. That is a bigger worry than the eyes, and it is worth telling the doctor who looks after the chest as well as me.

My teenager vapes. What does it do to the eyes?

The honest answer is that the evidence is thin and early. A 2021 review in International Ophthalmology found that aldehydes and free radicals in e-cigarette vapour may disturb the tear film, that corneal staining has appeared after vapour exposure, and that research on short- and long-term effects on the eye is limited. In a 2026 survey of 450 Palestinian university students, using both e-cigarettes and cigarettes went with more severe dry-eye symptoms (odds ratio 2.35), while e-cigarettes alone did not reach statistical significance.

The injury that is not a matter of statistics is the battery. Case reports describe e-cigarette explosions causing bilateral corneal burns and, in one case, a laceration through the wall of the eye. A burn or a blow to the eye from a device is a same-day problem; do not rub it, and go to emergency (is this urgent?).

The World Health Organization (WHO) states e-cigarettes are harmful to health and not safe, and that nicotine is highly addictive and harmful for adolescents whose brains are still developing. The eyes are the smaller part of that story. If you are going to start a conversation, begin with the dry, tired, red eyes he already complains about, because that is a door he may walk through, whereas "stop vaping" is a door he will close.

What should I change first, and when should I bring my child in?

Change the car first, then the rooms the child sleeps and plays in, then the smoker's own plan. In Malaysia, the Ministry of Health's mQuit service offers quitting support at health clinics, government hospitals and accredited private facilities, so the first step can be a klinik kesihatan visit.

That is not an eye matter, but it is the change that does most for your child's eyes, lungs and ears at once. For the adults in the house, Dr Catherine Chow, an oculoplastic surgeon, writes on thyroid eye disease, where stopping smoking is the strongest modifiable risk.

See me or another eye doctor soon if the redness or irritation lasts beyond a few days away from smoke, if the eyes are always sore, or if your child squints at the board or holds things close. Go the same day for a painful red eye, light that hurts, a change in sight, thick discharge, or any injury. Everything else is a child who has been near smoke and needs the smoke removed, and you have already started by reading this far.

Common questions

References

1. Survey of Ophthalmology · Secondhand smoke exposure and ocular health: a systematic review (Zhang et al., 2023) · pubmed.ncbi.nlm.nih.gov
2. Experimental Eye Research · The effect of active smoking, passive smoking, and e-cigarettes on the tear film: an updated comprehensive review (Miglio et al., 2021) · pubmed.ncbi.nlm.nih.gov
3. Photodiagnosis and Photodynamic Therapy · Postnatal passive smoking and risk of myopia in children and adolescents: a systematic review and meta-analysis (Yuan et al., 2026) · pubmed.ncbi.nlm.nih.gov
4. Acta Ophthalmologica · Maternal smoking during pregnancy and the risk of strabismus in offspring: a meta-analysis (Yang et al., 2019) · pubmed.ncbi.nlm.nih.gov
5. Nature Communications · Large-scale GWAS of strabismus identifies risk loci and provides support for a link with maternal smoking (He et al., 2025) · pubmed.ncbi.nlm.nih.gov
6. International Ophthalmology · The impact of vaping on ocular health: a literature review (Martheswaran et al., 2021) · pubmed.ncbi.nlm.nih.gov
7. BMC Ophthalmology · Electronic cigarette use and dry eye symptom severity among Palestinian university students (Sawaftah et al., 2026) · pubmed.ncbi.nlm.nih.gov
8. Cornea · Corneoscleral laceration and ocular burns caused by electronic cigarette explosions (Paley et al., 2016) · pubmed.ncbi.nlm.nih.gov
9. CDC · Secondhand smoke · www.cdc.gov
10. CDC · Health problems caused by secondhand smoke · www.cdc.gov
11. World Health Organization · Tobacco fact sheet · www.who.int
12. CodeBlue · KKM: 143 perokok daftar mQuit (Ministry of Health mQuit service) · codeblue.galencentre.org

By Dr Chan Li Yen. General information only. It does not replace a consultation. If you are worried about your child's eyes or vision, please see an eye doctor.