Sagarika Bordoloi, M. Optom

Assistant Professor, Assam Kaziranga University



Binocular vision (BV) dysfunctions are a group of neuromuscular disorders that may occur at any time once the BV functions are normally developed.(1) BV anomalies consist of accommodative anomalies and non-strabismic binocular dysfunctions which affect the binocularity of the subjects.(2)

Predictive factors

Not only myopia but also BV anomalies are found to be increased among children nowadays, mostly due to changes in the environment where near and intermediate visual tasks including the use of electronic gadgets, reading, writing, watching television and computer have been increased dramatically.(3) After refractive errors, BV disorders are the most common conditions among the population between 6 months to 18 years of age. (4)

While finding the prevalence of BV dysfunctions among rural school children in South Korea, the authors have discussed about the fact of finding a lower prevalence rate of the same in the rural area even with a larger sample as compared to the urban area. Because the urban children use to spend more time in study and less time in outdoor activities, depicting that their near workloads are higher which leads to a greater prevalence of BV dysfunctions. (5)

To maintain a clear vision during prolonged near work, high vergence and accommodative amplitude is required. The requirement of maintaining high accommodation and vergence for a longer time leads to intra- and extra ocular muscle weakness and finally shows numerous accommodative and vergence anomalies. Some other influencing factors which can be considered as a precursor to these anomalies are reading in poor illumination and/or in an abnormally close distance. Visual stress caused by factors such as prolonged near working hours and/or abnormal near working distance can influence the shift from orthophoria to near exophoria. (6,7)

It is reported that young individuals spend excessive time on computer games during their leisure time. (8) The users must pay close attention to the video display terminals which causes many symptomatic discomforts. (9)

Effective changes in the ergonomics in lifestyle

Performance of the binocular functions can be improved by involving in different outdoor physical activities such as exercises and sports on daily basis. Evidence shows that one can naturally improve visual motor skills by simply participating in physical exercises through interaction with the environment. (5,6,10–12) During exercise there is an alteration in ocular activities for example lens changing shape and ciliary muscle functions. (12) Sports also play a vital role in the different sensory and motor skills such as depth perception, ocular movements, near point of convergence, accommodative facility and vergence facility. People involved in sports like football, volleyball are found to be superior in all these functions to those who are not. (11,13)


BV dysfunctions are not uncommon among the pediatric population visiting an Optometry clinic. Therefore, it is preferable to diagnose and treat these dysfunctions properly by performing various standard test protocols. Also, the children and parents should be counselled that, by simply participating in physical outdoor and sports activities, they can make a significant improvement in BV skills and thus academic performances.



  1. American Optometric Association. Comprehensive Pediatric Eye and Vision Examination. Evid – Based Clin Pract Guidel. 2017. ( publications/clinical-practice-guidelines.)
  2. Cacho-Martínez P, García-Muñoz Á, Ruiz-Cantero MT. Do we really know the prevalence of accomodative and nonstrabismic binocular dysfunctions? J Optom. 2010;3(4):185-197. doi:10.1016/S1888-4296(10)70028-5
  3. Chandra P, Akon M. Non-Strabismic Binocular Vision Abnormalities. J Ophthalmol Vis Sci. 2016;1(1):9. visual-sciences/download%0Aissn: 2573-8593.
  4. Scheiman M, Gallaway M, Coulter R, et al. Prevalence of vision and ocular disease conditions in a clinical pediatric population. J Am Optom Assoc. 1996.
  5. Un J, Park I. Prevalence of general binocular dysfunctions among rural schoolchildren in South Korea. 2015;5.
  6. Lee J, Cho HG, Moon B, Kim S, Yu D. Effects of prolonged continuous computer gaming on physical and ocular symptoms and binocular vision functions in young healthy individuals. 2019:1-14. doi:10.7717/peerj.7050
  7. Pickwell D, Jenkins T, Yekta AA. the Effect on Fixation Disparity and Associated Heterophoria of Reading at an Abnormally Close Distance. Ophthalmic Physiol Opt. 1987;7(4):345-347. doi:10.1111/j.1475- 1313. 1987.tb00758.x
  8. Wittek CT, Finserås TR, Pallesen S, et al. Prevalence and Predictors of Video Game Addiction: A Study Based on a National Representative Sample of Gamers. Int J Ment Health Addict. 2016. doi:10.1007/s11469-015-9592-8
  9. Akinbinu TR, Mashalla YJ. Impact of computer technology on health: Computer Vision Syndrome (CVS). Med Pract Rev. 2014. doi:10.5897/2014/0121
  10. Woods RL, Thomson WD. Effects of exercise on aspects of visual function.
  11. Ophthalmic Physiol Opt. 1995;15(1):5-12. doi:10.1016/0275-5408(95)92786-E
  12. Omar R, Kuan YM, Zuhairi NA, Manan FA, Knight VF. Visual efficiency among teenaged athletes and non-athletes. Int J Ophthalmol. 2017;10(9):1460-1464. doi:10.18240/ijo.2017.09.20
  13. Govender C, Grant R, Kleynhans M. Evaluation of visual skills in sedentary and active work environments. 2012:1
  14. Jafarzadehpur E, Aazami N, Bolouri B. Comparison of saccadic eye movements and facility of ocular accommodation in female volleyball players and non-players. 2007:186-190. doi:10.1111/j.1600-0838.2005.00535.