1. University of Szczecin, Department of Physical Culture and Health Promotion , Al. Piastów 40 b blok 6, 71-065 Szczecin, Poland
2. Department and Clinic of Ophthalmology, Pomeranian Medical University, Szczecin, Poland
3. Department of Physical Culture and Health Promotion, University of Szczecin, Szczecin, Poland
4. Institute of Vision Training and Therapy, Warszawa, Poland
5. Institute of Mathematics, University of Szczecin, Szczecin, Poland