Excessive Smartphone Use Can Cause Acute Acquired Comitant Esotropia

As digital devices like smartphones become ubiquitous, the number of youngsters suffering from a vision disorder called strabismus is on the rise

The disorder causes eyes to not properly align with each other when looking at an object. Strabismus can cause the eyes to cross in (esotropia) or turn out (exotropia).

Ophthalmologists are urging limits on excessive cell phone use by children.

Koji Kawamoto, an ophthalmology specialist in Japan, published a book Smartphone and Blindness in 2022. He wrote that spending a lot of time looking at a smartphone can cause one’s eyes to be fixed in an inward-focus position.

In the long run, it can cause “acute acquired comitant esotropia (AACE).” AACE often occurs in myopic patients who look at close objects for a long time.

AACE is a temporary condition that can be relieved by avoiding looking at close objects. However, with long-term use of smartphones, esotropia symptoms become difficult to improve. An increasing number of patients require surgical treatment.

According to a questionnaire-based report by the Japanese Association of Pediatric Ophthalmology and the Association for Strabismus and Amblyopia in 2019, 158 out of 371 ophthalmologists consulted AACE patients aged between 5 to 35 in 2018. And 122 ophthalmologists said the disease was related to the excessive use of digital devices like smartphones, especially among youngsters under 12 years old.

AACE And Exessive Use Of 3C Products

Dr. Weng Shaowei, an ophthalmologist in Taiwan, said that the incidence of AACE has increased among young people aged 10 to 20 due to the excessive use of “3C” (computers, communication, and consumer) electronic products.

Weng said that esotropia is usually induced by other diseases such as high refractive error, extraocular muscle injury, inflammation, hyperthyroidism, myasthenia gravis, chronic rhinosinusitis, and surgical sequelae. The pressure on the nerve from a brain tumor could also induce the condition.

If an adult suddenly develops AACE, he or she will see two images when looking at one object. The patient cannot visually merge the image; this inability is called “diplopia.”

Weng said that when people look at their phones, the viewing distance is about 20 to 30 centimeters, affecting their visual merging ability in the long run. Moreover, for people with esotropia, the symptoms can quickly develop into AACE.

When systemic disease, inflammation, external injury, and brain problems are excluded as the cause of esotropia, ophthalmologists will use Botulinum toxin (Botox) therapy to relax excessive muscle contractions without surgery. Unfortunately, the treatment might not cure patients with AACE. Some relapse after receiving Botox therapy and eventually need surgery or prism glasses.

Weng suggests that parents prevent long-term use of 3C products by children. When your child complains about diplopia, fatigue, or headache or closes one eye under bright sunlight, you should be very careful as the child might have already developed symptoms of esotropia.

Take the child to the doctor as soon as possible. If one suffers from very large angle esotropia, which cannot be quickly cured, it will cause a great deal of inconvenience. For children, long-term esotropia could damage visual function and even lead to amblyopia (also called “lazy eye”).

Zheng Jie, Ph.D. in medical science from the University of Tokyo in Japan, said in an interview with The Epoch Times that teenagers who are still developing their visual functions should pay attention to the following points:

  • Maintain a screen-to-eye distance of 50cm for computers and 30cm or more for smartphones;
  • Limit time playing video games or looking at a smartphone every day;
  • When using a screen, remember to look away at a distant object after each period of 10 to 20 minutes;
  • Participate in outdoor activities.


March 31, 2023


Leave A Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.

This website uses cookies to improve your experience. We'll assume you're ok with this, but you can opt-out if you wish. Accept Read More