Digital Device-Associated AACE

Also termed “smartphone-associated AACE” — an increasingly recognized clinical phenotype of acute-acquired-concomitant-esotropia distinct from the classical burian-miller-classification subtypes. ¹

Key Characteristics

• Very short viewing distances (<20 cm)
• Extended daily screen time
• High accommodative-convergence demand
• Reduced outdoor viewing
• Strongest in children, adolescents, and young adults

Epidemiological Signal

• Dramatic case increase beginning ~2020, coinciding with COVID-19 lockdowns and online learning
• Higher prevalence in East Asian populations
• Multiple recent studies strongly support the association between smartphone overuse and AACE onset

Proposed Mechanism

Sustained near fixation at smartphone distances (~20 cm) imposes extreme accommodative-convergence load. Over time, this may:

1. Increase tonic convergence tone
2. Shorten convergence adaptation
3. Deplete divergence fusional reserves
4. Trigger decompensation into manifest esotropia

This differs mechanistically from classical subtypes — the trigger is behavioral/technological rather than optical (Type I), psychological (Type II), or myopic (Type III). ¹

Clinical Implications

• Digital history should be part of AACE workup
• Device restriction may help in early cases (though inconsistent once deviation is established)
• Suggests a preventive ophthalmology dimension: screen hygiene, viewing distance, outdoor activity

See Also

• acute-acquired-concomitant-esotropia
• burian-miller-classification
• vergence-control
• digital-therapeutics-for-vergence

Footnotes

1. raw/articles/aace-comprehensive-review-2026.md ↩ ↩²