1. Crowding ratio in young normally sighted children.
- Author
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Dekker MJ, Pilon F, Bijveld MM, de Wit GC, and van Genderen MM
- Subjects
- Child, Child, Preschool, Female, Humans, Male, Reference Values, Sensory Thresholds, Vision Tests instrumentation, Vision, Binocular physiology, Form Perception physiology, Perceptual Distortion physiology, Vision Disorders physiopathology, Visual Acuity physiology
- Abstract
Purpose: To determine normal values of the crowding ratio (CR) in children., Methods: Of 62 normally sighted primary school children aged 4-12 years old the CR was determined both for distance and near vision. The examinations were performed using commonly available test charts based on the LEA symbols., Results: At near, the CR was significantly better than at distance and for all ages <2.0. The upper limit of the CR at distance was <2.0 from age six., Conclusion: With commonly available tests the CR can easily be determined in school age children. For children >6 years of age, a CR > 2.0 (i.e. at least 3 lines difference between the result of a single optotype acuity test and a line acuity test) is suspicious and warrants further investigation. It may, for example, be a sign of cerebral visual impairment (CVI).
- Published
- 2012
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