SymptomEyes & vision
Squinting: Causes in Children and Adults
Squinting means partly closing the eyes to see more clearly or to block out light. Narrowing the eyelids works like a pinhole camera and briefly sharpens blurry vision, so frequent squinting is a classic sign of an uncorrected refractive error such as nearsightedness or astigmatism. It can also come from light sensitivity, dry eye or eye strain. In British English, "a squint" means misaligned eyes (strabismus), which is a different problem that also needs an eye exam, especially in children.
Also called: Screwing up the eyes, narrowing the eyes, partly closing the eyes, squint (UK term for strabismus)
At a glance
- What it is
- Narrowing the eyelids to sharpen focus or reduce glare.
- Most common cause
- Uncorrected nearsightedness, astigmatism or farsightedness.
- Other causes
- Light sensitivity, dry eye, eye strain, migraine, eye inflammation.
- In children
- A common early clue to needing glasses; can also signal a turned eye.
- Next step
- An eye exam with an optometrist or ophthalmologist.
- Treatment
- Glasses or contact lenses, treating dry eye or light sensitivity, eye exercises or patching for strabismus.
When to get help
Call 911 or go to the ER
- Sudden squinting from severe eye pain, especially with a red eye, blurred vision, headache and nausea
- Squinting after a chemical splash or an object hitting the eye
See a doctor within a day or two
- Squinting with a painful red eye and light sensitivity (possible iritis or corneal infection), especially in contact lens wearers
- Squinting with a feeling of something in the eye that does not wash out
- New double vision or a newly turned eye in a child or adult
Book a routine appointment
- A child who squints, sits close to the TV, holds books close or rubs their eyes often
- An eye that turns in, out, up or down, even occasionally, in a child over 4 months
- Squinting to read small print or road signs
- Squinting with frequent headaches after reading or screen use
Usually safe to manage at home
- Squinting in bright sunlight, eased by sunglasses
- Occasional squinting when tired after long screen use
Why squinting helps you see
When you squint, the eyelids narrow the opening of the eye. This blocks light rays coming in at angles, which are the rays that blur most in an eye that does not focus perfectly. The result is a sharper image, just like a pinhole camera. Squinting also cuts the amount of light entering the eye, which helps in glare.
Because it works, people with mild vision problems often squint without realizing it.
Causes of squinting
| Cause | Clues |
|---|---|
| Myopia (nearsightedness) | Distance blurry: whiteboard, TV, road signs |
| Astigmatism | Blurry or distorted at all distances, glare around lights at night |
| Hyperopia (farsightedness) | Near tasks tiring, headaches with reading; children may squint or have a turned eye |
| Presbyopia | After 40: difficulty reading small print, holding things farther away |
| Light sensitivity (photophobia) | Discomfort in bright light; migraine, eye inflammation, after dilation |
| Dry eye | Gritty, burning eyes; blurry vision that clears with blinking |
| Eye strain | After long screen or near work; tired eyes and headache |
| Cataract | Glare, halos and faded colors in older adults |
| Corneal problems | Pain, redness, tearing; abrasion, ulcer or keratitis |
Squinting in bright light
Everyone squints somewhat in bright sun. Excessive sensitivity can be normal for people with light-colored eyes, but it also occurs with migraine, eye inflammation (uveitis), corneal problems, cataracts, and after concussion. Squinting with one eye closed in bright sunlight is a classic sign of intermittent exotropia in children, where one eye drifts outward.
Squinting in children
Children rarely complain about blurry vision because they assume everyone sees the way they do. Watch for:
- squinting or closing one eye to see
- sitting very close to the TV or holding devices near the face
- frequent eye rubbing, tearing or blinking
- tilting the head to look at things
- avoiding reading or losing their place
- headaches or tired eyes after school
- poor performance in school or sports
Nearsightedness typically starts between ages 6 and 14 and often progresses through the teen years. Spending more time outdoors in childhood appears to reduce the risk of developing myopia.
Squint meaning a turned eye
In the UK and elsewhere, "a squint" means strabismus: eyes that do not point in the same direction. An eye may turn in (esotropia), out (exotropia), up or down, all the time or only when tired. Brief, occasional wandering can be normal in babies up to about 4 months. After that, a turned eye needs assessment, because the brain may start ignoring the weaker eye, leading to amblyopia (lazy eye). Treatment works best when started early, ideally before age 7 to 8.
How eye doctors find the cause
An optometrist or ophthalmologist will:
- check vision at distance and near using letter charts (or pictures for young children)
- measure refractive error, often with eye drops in children to relax focusing
- check eye alignment and movement with cover tests
- examine the front of the eye and the retina
- assess tear film and dryness if relevant
US pediatric guidelines recommend vision screening at well-child visits from early childhood, and a full eye exam for any child who fails screening or shows signs such as squinting or a turned eye.
Treatment
- Glasses or contact lenses correct refractive errors and usually stop squinting immediately.
- Myopia control in children: low-dose atropine drops, special contact lenses or spectacle lenses can slow progression.
- Strabismus: glasses, patching or drops to strengthen the weaker eye, eye exercises for some types, and sometimes surgery on the eye muscles.
- Dry eye: artificial tears, warm compresses and screen breaks.
- Light sensitivity: sunglasses with UV protection, a brimmed hat, and treating the underlying cause, such as migraine.
- Eye strain: the 20-20-20 rule (every 20 minutes, look 20 feet away for 20 seconds), good lighting, and correct prescription for screen distance.
Frequently asked questions
Why do I squint to see clearly?
Squinting narrows the opening of your eye, which reduces blur from a refractive error, much like a pinhole. If you need to squint to see clearly, you probably have uncorrected nearsightedness, farsightedness, astigmatism or presbyopia. An eye exam and glasses usually fix it.
Does squinting mean my child needs glasses?
Often, yes. Frequent squinting, sitting close to screens and holding books close are common signs of nearsightedness or astigmatism in children. Book an eye exam. Squinting can also signal a turned eye, which is important to treat early.
Is squinting bad for your eyes?
Squinting does not damage your eyes, but frequent squinting can cause eye strain, headaches and forehead tension, and it signals that your vision may need correcting. Treating the cause, usually with glasses, removes the need to squint.
What is the difference between squinting and a squint?
Squinting is narrowing the eyelids to see better or block light. "A squint" is a British term for strabismus, where the eyes point in different directions. Both deserve an eye exam, but a turned eye in a child needs prompt attention to prevent lazy eye.
Sources
This guide was written from current patient and clinical guidance, including:
- American Academy of Ophthalmology: Nearsightedness (myopia)
- American Academy of Pediatrics and American Academy of Ophthalmology: Vision screening for infants and children
- American Optometric Association: Computer vision syndrome
- NHS: Squint in children
- National Eye Institute: Refractive errors