Poor binocular coordination of saccades in dyslexic children



To examine the quality of binocular coordination of saccades in dyslexic children in single word reading and in a task requiring fixation of single LED.


Eighteen children with dyslexia (11.4 ± 2 years old) and 13 non-dyslexic children of matched age were studied. Horizontal saccades from both eyes were recorded with a photoelectric system (Oculomotor-Bouis).


Binocular coordination during and after the saccade in dyslexics is worse than that of non-dyslexic children; the disconjugacy does not depend on the condition. Moreover, dyslexics do not show the stereotyped pattern of disconjugacy (divergence during the saccade and convergence after the saccade). The conjugate post-saccadic drift is larger in dyslexics for both conditions.


Poor quality of binocular coordination of saccades and drift of the eyes after the saccade, regardless of the task, indicates an intrinsic ocular motor deficiency. Such a deficiency could be related to immaturity of the normal ocular motor learning mechanisms via which ocular motor coordination and stable fixation are achieved. Learning could be based on the interaction between the saccade and vergence subsystems. The cerebellum, but also cortical areas of the magnocellular stream such as the parietal cortex, could be the sites of ocular motor learning.

This is a preview of subscription content, log in to check access.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5


  1. 1.

    Pavlidis GT (1981) Do eye movements hold the key to dyslexia? Neuropsycologia 19:57–64

    Article  CAS  Google Scholar 

  2. 2.

    Rayner K (1988) Eye movements in reading and information processing: 20 years of research. Psychol Bull 124(3):372–422

    Article  Google Scholar 

  3. 3.

    Brown B, Haegerstrom-Portnoy G, Yingling CD, Herron J, Galin D, Marcus M (1983) Tracking eye movements are non-dyslexic in dyslexic children. Am J Optom Physiol Opt 60(5):376–383

    PubMed  CAS  Google Scholar 

  4. 4.

    Olson RK, Kliegl R, Davidson BJ (1983) Dyslexic and non-dyslexic readers’ eye movements. J Exp Psychol Hum Percept Perform 9(5):816–825

    PubMed  Article  CAS  Google Scholar 

  5. 5.

    Habib M (2000) The neurological basis of developmental dyslexia. An overview and working hypothesis. Brain 123:2373–2399

    PubMed  Article  Google Scholar 

  6. 6.

    Lovegrove WJ, Bowling A, Badcock D, Blackwood M (1990) Specific reading disability: differences in contrast sensitivity as a function of spatial frequency. Science 210(4468):439–440

    Article  Google Scholar 

  7. 7.

    Livingstone MS, Rosen GD, Drislane FW, Galaburda AM (1991) Physiological and anatomical evidence for a magnocellular defect in developmental dyslexia. Proc Natl Acad Sci USA 88(18):7943–7947

    PubMed  Article  CAS  Google Scholar 

  8. 8.

    Stein J, Walsh V (1997) To see but not to read; the magnocellular theory of dyslexia. Trends Neurosci 20(4):147–152

    PubMed  Article  CAS  Google Scholar 

  9. 9.

    Stein JF, Fowler MS (1993) Unstable binocular control in dyslexic children. J Res Read 16:30–45

    Article  Google Scholar 

  10. 10.

    Eden GF, Stein JF, Wood HM, Wood FB (1994) Differences in eye movements and reading problems in dyslexic and non-dyslexic children. Vision Res 34(10):1345–1358

    PubMed  Article  CAS  Google Scholar 

  11. 11.

    Fioravanti F, Inchingolo P, Pensiero S, Spanio M (1995) Saccadic eye movement conjugation in children. Vis Res 35:3217–3229

    PubMed  Article  CAS  Google Scholar 

  12. 12.

    Yang Q, Kapoula Z (2003) Binocular coordination of saccades at far and at near in children and in adults. J Vis 3:554–561

    PubMed  Article  Google Scholar 

  13. 13.

    Bucci MP, Kapoula Z (2006) Binocular coordination of saccades in 7 years old children in single word reading and target fixation. Vis Res 46(4):457–466

    PubMed  Article  Google Scholar 

  14. 14.

    Bucci MP, Kapoula Z, Bremond-Gignac D, Wiener-Vacher S (2006) Binocular coordination of saccades in children with vertigo: dependency on the vergence state. Vis Res 46:3594–3602

    PubMed  Article  Google Scholar 

  15. 15.

    Chevrie-Muller C, Simon AM, Fournier S (1997) Batterie Langage oral écrit. Mémoire. Attention (L2MA) Paris, Editions du Centre de Psychologie appliquée

  16. 16.

    Riddell PM, Fowler MS, Stein JF (1990) Spatial discrimination in children with poor vergence control. Percept Mot Skills 70(3 Pt 1):707–718

    PubMed  Article  CAS  Google Scholar 

  17. 17.

    Stein JF, Riddell PM, Fowler MS (1987) Fine binocular control in dyslexic children. Eye 1(Pt 3):433–438

    PubMed  Google Scholar 

  18. 18.

    Stein JF, Riddell PM, Fowler S (1988) Disordered vergence control in dyslexic children. Br J Ophthalmol 72(3):162–166

    PubMed  Article  CAS  Google Scholar 

  19. 19.

    Vitu F, Kapoula Z, Lancelin D, Lavigne F (2004) Eye movements in reading isolated words : evidence for strong biases towards the center of the screen. Vis Res 44(3):321–338

    PubMed  Article  Google Scholar 

  20. 20.

    Bucci MP, Kapoula Z, Yang Q, Roussat B, Bremond-Gignac D (2002) Binocular coordination of saccades in strabismic children before and after surgery. Investig Ophthalmol Vis Sci 43(4):1040–1047

    Google Scholar 

  21. 21.

    Bucci MP, Kapoula Z, Bremond-Gignac D, Wiener-Vacher S (2004) Speed-accuracy of saccades, vergence and combined movements in children with vertigo. Exp Brain Res 157(3):286–295

    PubMed  Article  Google Scholar 

  22. 22.

    Kapoula Z, Bucci MP, Jurion F, Ayoun J, Afkhami F, Brémond-Gignac D (2007) Evidence for frequent divergence impairment in French dyslexic children: deficit of convergence relaxation or of divergence per se? Graefes Arch Clin Exp Ophthalmol 245:931–936

    PubMed  Article  Google Scholar 

  23. 23.

    Heller D, Radach R (1999) Eye movements in reading. Are two eyes better than one? In: Becker (ed) Current oculomotor research. Plenum Press, New York

    Google Scholar 

  24. 24.

    Kapoula Z, Bucci MP, Ganem R, Poncet S, Daunys G, Brémond-Gignac D. Free exploration of painting uncovers particularly loose yoking of saccades in dyslexics. Dyslexia (submitted)

  25. 25.

    Collewijn H, Erkelens CJ, Steinman RM (1988) Binocular co-ordination of human horizontal saccadic eye movements. J Physiol 404:157–182

    PubMed  CAS  Google Scholar 

  26. 26.

    Collewijn H, Erkelens CJ, Steinman RM (1997) Trajectories of the human binocular fixation point during conjugate and non-conjugate gaze-shifts. Vision Res 37(8):1049–1069

    PubMed  Article  CAS  Google Scholar 

  27. 27.

    Sylvestre PA, Galiana HL, Cullen KE (2002) Conjugate and vergence oscillations during saccades and gaze shifts: implications for integrated control of binocular movement. J Neurophysiol 87(1):257–272

    PubMed  Google Scholar 

  28. 28.

    Galaburda AM, Sherman GF, Rosen GD, Aboitiz F, Geschwind N (1985) Developmental dyslexia: four consecutive patients with cortical anomalies. Ann Neurol 18(2):222–233

    PubMed  Article  CAS  Google Scholar 

  29. 29.

    Kapoula Z, Evdokimidis I, Smyrnis N, Bucci MP, Constandinidis T (2002) Slow evoked potentials prior movements of the eyes in 3D space. NeuroReport 13:1893–1897

    PubMed  Article  Google Scholar 

  30. 30.

    Kapoula Z, Yang Q, Coubard O, Daunys G, Orssaud C (2004) Effects of transcranial magnetic stimulation of the posterior cortex on isolated and combined saccade-vergence movements. Neurosci Lett 360:95–99

    PubMed  Article  CAS  Google Scholar 

  31. 31.

    Tzelepi A, Lutz A, Kapoula Z (2004) EEG activity related to preparation and suppression of eye movements in 3-D space. Exper Brain Res 155(4):439–449

    Article  Google Scholar 

  32. 32.

    Mishkin M, Ungerleider LG (1982) Contribution of striate inputs to the visuospatial functions of parieto-preoccipital cortex in monkeys. Behav Brain Res 6(1):57–77

    PubMed  Article  CAS  Google Scholar 

  33. 33.

    Ygge J, Lennerstrand G, Axelsson I, Rydberg A (1993) Visual functions in a Swedish population of dyslexic and non-dyslexicly reading children. Acta Ophthalmol 71(1):1–9

    CAS  Article  Google Scholar 

  34. 34.

    von Noorden GK (2002) Binocular vision and ocular motility. Theory and management of strabismus. 6th ed. Mosby, St. Louis

    Google Scholar 

Download references


The authors are grateful to the Service de Psychopathologie de l’enfant et de l’adolescent (Dr. M.-F. Le Heuzey et Pr. M.-C. Mouren-Simeoni) at the pediatric hospital Robert Debré (referred center for a complete evaluation of the dyslexia state). The authors thank all children who participated in the study. F. Afkhami (orthoptist), J. Ayoun and F. Jurion (optometrists) conducted the visual examination of the children; Dr. R. Bertin corrected the linguistic content of the manuscript.

Author information



Corresponding author

Correspondence to Maria Pia Bucci.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Bucci, M.P., Brémond-Gignac, D. & Kapoula, Z. Poor binocular coordination of saccades in dyslexic children. Graefes Arch Clin Exp Ophthalmol 246, 417–428 (2008). https://doi.org/10.1007/s00417-007-0723-1

Download citation


  • Dyslexia
  • Children
  • Binocular coordination
  • Saccades
  • Vergence