An underappreciated consequence of the COVID-19 Pandemic:
Excessive screen time disrupts normal oculomotor development

In these unusual times as we try to keep our physical distance while socially isolating, we are all abusing screens to stay social and retain some semblance of normal life. Our children are no exception. Therefore, as we use technology to remain closer, we must take caution and pay attention to our children so that they do not damage their fragile visual system. Pending schools reopening, we call on you, as parents, to be vigilant. We encourage alternative methods of teaching that do not rely on a screen in order to ensure our children’s physical and mental development remains on track.

Dr. Zoi Kapoula & Lindsay Ward, MD

For more information, see video:
Pour site UK :
Pour site FR :

Screen time in Dyslexic Adolescents

We have found that dyslexic adolescents spend significantly more time on the computer than non-dyslexic adolescents (31 hours vs 14 hours per week), while simultaneously reporting increased visual stress and symptoms (Convergence Insufficiency Symptom Survey, score of 24 vs 17). 1,2 These children have also demonstrated a decreased capacity to release convergence and diverge their eyes to the far space , a difficulty in keeping the vergence angle stable during the fixations following the saccades, which ultimately impacts quality of vision, attention, and reading (publication in progress Ward L. & Kapoula Z.).

Dr. Zoi Kapoula & Lindsay Ward, MD

1. Ward L, Kapoula Z. Differential Diagnosis of Vergence and Saccade Disorders in Dyslexia, under review, Scientific Reports. 2020.
2. Rouse, M. et al. Validity of the convergence insufficiency symptom survey: a confirmatory study. Optom Vis Sci 86, 357-363, 2009.

Neuroplasticity of Binocular Eye Movements in Dyslexia

With specific neurorehabilitation programs, the eye movement problems in dyslexic children or adolescents can be overcome thanks to the neuroplasticity that is retained in youth. Indeed, Depreux & Kapoula have demonstrated an improvement in vergence eye movements and reading scores after only two sessions of neurorehabilitation in dyslexic teenagers. The method used for vergence neurorehabilitation was the REMOBI, that has been previously successfully tested for adults.

Zoi Kapoula & Pauline Depreux

1. Depreux P, Kapoula Z. Perspectives de réhabilitation des mouvements oculaires chez les enfants dyslexiques. Orthoptie, Haute Ecole de Province de Liège, Belgique, Master thesis, 2020.
2. Kapoula, Z. et al. Objective Evaluation of Vergence Disorders and a Research-Based Novel Method for Vergence Rehabilitation. Transl Vis Sci Technol 5, 8, doi:10.1167/tvst.5.2.8 (2016).

Deterioration of binocular eye movements after only two hours of screen use

Prolonged use of screens has been shown to greatly increase visual strain and rigidity of eye accommodation. Yet, objective eye movement studies were missing. Our study in ten healthy students has shown, for the first time, that even two hours of screen time is sufficient to deteriorate the binocular coordination and the speed of their saccades, reduce their divergence capacity (i.e. the ability to move their eyes from a near space to far); in turn, their accommodative convergence increased abnormally. The study was carried with the REMOBI & AIDEAL technologies.

Zoi Kapoula & Léa Buns

1. Sheppard AL, Wolffsohn JS. Digital eye strain: prevalence, measurement and amelioration. BMJ Open Ophthalmol. 2018;3(1):e000146.
2. Collier JD, Rosenfield M. Accommodation and convergence during sustained computer work. Optometry. 2011;82(7):434-440.
3. Buns L, Kapoula Z. L’impact des écrans sur les mouvements oculaires. Master thesis, Optométrie Sciences de la Vision, Université Paris Saclay, 2020.