1 20.09.2016

Department of Process, Energy, and Environmental Technology, Telemark University College, Kjølnes Ring 56, Postbks 203, 3910 Porsgrunn, NorwayS. e-mail:

1 Pandemic Centre, University of Bergen, Norway, 2 Department for Global Public Health and Primary Care, Faculty of Medicine, University of Bergen, Norway, 3 Unit for Migration

1 Department of Global Public Health and Primary Care, University of Bergen, PO Box 7804, 5020 Bergen, Norway. 2 Department of Psychosocial Health, University of Agder, PO Box 422,

National Centre for Optics, Vision and Eye Care, Department of Optometry, Radiography and Lighting Design, Faculty of Health and Social Sciences, University of South-Eastern

1 National Centre for Optics, Vision and Eye Care, Department of Optometry, Radiography and Lighting Design; Faculty of Health and Social Sciencess, University of South-Eastern

1 National Centre for Optics, Vision and Eye Care; Department of Optometry, Radiography and Lighting Design; Faculty of Health and Social Sciences, University College of

National Centre for Optics, Vision and Eye Care, Department of Optometry and Visual Science, Faculty of Health Science, University College of Southeast Norway, Kongsberg, 3616,

Department of Optometry and Visual Science, Faculty of Health Sciences, Buskerud and Vestfold University College, Kongsberg, 3616, Norway.. * Corresponding