STEPHANIE WEST CONSULTANT OPHTHALMIC SURGEON
Specialist squint, double vision and children’s eye care in Southampton
Intermittent Exotropia
Intermittent exotropia is a common type of childhood squint in which one eye occasionally drifts outwards. The eyes may appear straight for much of the day; however, the drift can become more noticeable when a child is tired, daydreaming, unwell, looking into the distance or standing in bright sunlight.
What does intermittent exotropia look like?
Intermittent exotropia: the eyes may be straight most of the time; however, one eye can drift outwards when a child is tired, daydreaming, unwell or looking into the distance.
Comes and goes
The eye may be straight most of the time and drift only in particular situations.
Often worse when tired
Parents commonly notice the drift at the end of the day or during illness.
Bright-light eye closure
Some children close one eye outdoors because bright light makes control more difficult.
Usually good vision
Most children retain useful vision and binocular function, especially when the squint remains intermittent.
Signs parents may notice
- One eye drifting out when your child is tired or daydreaming
- Closing one eye in bright sunlight
- Frequent blinking, eye rubbing or refocusing
- The eye taking longer to straighten again
- Occasional headaches or visual discomfort
- Concerns about appearance, confidence or social interaction
Young children rarely report double vision. Therefore, photographs or short videos taken at home can be very useful when the drift is not seen during the appointment.
What happens at the assessment?
First, an orthoptist measures vision in each eye and checks how often the squint appears. Next, the ability to regain alignment and maintain 3D vision is assessed. In addition, Stephanie may use dilating drops to measure the glasses prescription and examine the health of the eyes.
The assessment may include:
- Visual acuity in each eye
- Distance and near alignment
- Control of the outward drift
- Depth perception or stereo vision
- Eye movements
- Glasses prescription
Monitor or treat?
Many children need monitoring only. In UK studies referenced in Stephanie’s patient information, around 53% remained under observation, while progression to a constant exotropia was uncommon. Nevertheless, review remains important because control can change over time.
How often does the eye drift?
Occasional drifting with good control often supports monitoring.
Can your child realign it?
Difficulty regaining alignment may suggest declining control.
Is vision or confidence affected?
Reduced 3D vision, symptoms or social impact may support treatment.
Monitoring
Monitoring is often appropriate when the drift is infrequent, the child can straighten the eye easily and binocular vision remains good. As a practical guide, mild cases may be monitored when the eye drifts for less than half of waking hours.
At each review, the orthoptist checks whether the squint is becoming more frequent, whether recovery is slower and whether depth perception is changing.
Non-surgical treatment
Glasses: spectacles may improve control when a refractive error is present. Short-sighted children may benefit particularly from accurate correction.
Over-minus lenses: these can sometimes stimulate focusing and improve control; however, they may increase myopia and are therefore used selectively.
Exercises: exercises may help selected near-coordination problems, although they do not treat every distance exotropia.
Squint surgery
Surgery may be considered when the eye drifts for more than half of waking hours, control is declining, 3D vision is reducing or the appearance is affecting confidence.
The operation may weaken both outer eye muscles, or combine weakening of an outer muscle with tightening of an inner muscle. Because results vary, an overcorrection or undercorrection can occur and further surgery may occasionally be needed.
When should you contact us sooner?
- The eye is drifting more often or for longer periods
- Your child can no longer straighten the eye easily
- There is new double vision, headache or a change in vision
- Your child is becoming self-conscious or being affected socially
- The squint appears constant rather than intermittent
A useful tip for appointments
Bring several photographs or short videos showing the eye drift at home. Ideally, include examples when your child is tired, looking into the distance or outdoors. This helps the clinical team understand how often the exotropia appears in everyday life.
Related children’s eye information
Squints in children
An overview of inward, outward and vertical childhood squints.
Children’s eye tests
How orthoptists assess vision, alignment and depth perception.
Squint surgery
What parents can expect before, during and after treatment.
Frequently asked questions
Many cases remain stable. However, regular review is important because control can deteriorate in a small proportion of children.
Bright light can make control of an outward squint more difficult, so some children close one eye to avoid visual confusion.
No. Many children are monitored without treatment, particularly when the drift is infrequent and binocular vision remains good.
Yes, especially when short-sightedness or another glasses prescription affects control. Over-minus lenses are used selectively because they can accelerate myopia.
Exercises may help selected convergence difficulties but are not a universal treatment for distance intermittent exotropia.
Surgery may be discussed when drifting occurs frequently, control worsens, 3D vision declines or the squint affects confidence and quality of life.
Yes. Overcorrection, undercorrection or later drift can occur, and some children need more than one operation.
Yes. Photos and short videos can show how the squint behaves at home when it is not present during the clinic examination.
Concerned about an outward eye drift?
Arrange a specialist orthoptic and ophthalmic assessment for clear advice about monitoring and treatment.