Aims: Papers I & II: To evaluate the consequences of changes in the criteria for referral to an eye clinic following general pre-school vision screening. According to the former criteria all 4 year old children in the Göteborg area, with visual acuity (VA) 70%) of the children with slightly reduced vision at the age of 4 years had a visual acuity of 0.8 or better. Few had visual defects needing treatment and among those who were treated, the results were good. Papers III-V: Ophthalmologic abnormalities were common in children born before 29 gestational weeks. These children had a smaller optic disc area, neuroretinal rim area and more than normal tortuosity of retinal vessels. Reduced visual perception was observed in 40% of the children born before 29 weeks of gestation and in 67% of children in the patient-based group with brain lesions or signs that might indicate a brain lesion.Conclusions: Papers I & II: The alteration of the screening criteria has resulted in a reduction of unnecessarily referred children while few children in need of treatment are missed. Papers III-V: Prematurely born children are at increased risk for visual problems and ocular abnormalities. Reduced visual perception is common in preterm children even in those without a diagnosis of a brain lesion. Strabismus and subnormal visual acuity in a prematurely born child should alert the ophthalmologist to the possible existence of visual perceptual problems
