Visual fixation development in children

Abstract

Background: The ability to keep steady fixation on a target is one of several aspects of good visual function. However, there are few reports on visual fixation during childhood in healthy children.

Methods: An infrared eye-tracking device (Orbit) was used to analyse binocular fixation behaviour in 135 non-clinical participants aged 4-15 years. The children wore goggles and their heads were restrained using a chin and forehead rest, while binocularly fixating a stationary target for 20 s.

Results: The density of fixations around the centre of gravity increased with increasing age (p < 0.01), and the time of fixation without intruding movements increased with increasing age (p = 0.02), while intruding saccades decreased with increasing age (p < 0.01). The number of blinks and drifts did not differ between 4 and 15 years, and there were no significant differences with regard to gender or laterality in any of the investigated variables. No nystagmus was observed.

Conclusion: This study establishes values for visual fixation behaviour in a non-clinical population aged 4-15 years, which can be used for identifying children with fixation abnormalities.