[Vision Screening in Zurich]

In the city of Zurich, vision screening is performed by school medical services as part of the legally compulsory preventive medical examinations. We retrospectively evaluated the results of the 2011-2012 school year.

Preventive medical examinations by the school medical services were performed in all kindergartens. The examinations were mandatory for first, second and eighth grade children, whilst those for the fourth grade were voluntary. The basic diagnostic testing consisted of monocular visual acuity (Snellen E chart) for all age groups and the stereopsis test (TNO test) in kindergartens.

Vision screening was performed on 7499 children. 1471 first graders (55 %), 201 fourth graders (11 %) and 211 eighth graders (12.3 %) did not pass the examinations. In 33.7 % of the children who underwent the follow-up examination from an ophthalmologist, amblyogenic potential was found.

Vision screening by the school medical services enrols most of the children from a single age group. The Snellen E charts used for the monocular distance acuity, together with the TNO stereo test, appear to constitute an effective testing combination. Ophthalmological follow-up examinations of the affected children revealed that one third were afflicted by amblyogenic factors.