Exotropia is an outward turning of one or both eyes. It can be constant or appear only at times.
Childhood and developmental causes
In children, exotropia often arises from imbalance between the eye muscles or control systems. It may first appear when the child is tired or daydreaming.
- Intermittent exotropia that drifts mainly when looking far away
- Congenital exotropia present from early infancy
- Family history of squint or refractive error
- Occasionally linked with neurological or developmental conditions
Adult-onset causes
New exotropia in adults often produces double vision and needs assessment. Causes range from decompensated childhood squint to nerve or muscle problems.
- Loss of fusion control after illness, stress, or visual change
- Cranial nerve palsies affecting eye muscles
- Thyroid eye disease or trauma disrupting alignment
- Any recent-onset outward turn should be checked urgently
