1. Department of Special Education; Stockholm University; Stockholm Sweden
2. Swedish National Agency for Special Needs Education and Schools; Stockholm Sweden
3. Department of Paediatric Ophthalmology and Strabismus; St. Erik Eye Hospital; Karolinska Institutet; Stockholm Sweden
4. Gillberg Neuropsychiatry Centre; Institute of Neuroscience and Physiology; University of Gothenburg; Gothenburg Sweden