1. Eye Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
2. Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran
3. Health Promotion Research Center, Zahedan University of Medical Sciences, Zahedan, Iran
4. Miguel Hernandez University, Alicante, Spain and Vissum Miranza, Alicante, Spain