Crowding Ratio in Young Normally Sighted Children

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 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).