1. Vestibular and Ocular Motor Research Group, Department of Neuroscience, Erasmus MC, P.O. Box 2040, 3000 CA Rotterdam, Netherlands
2. Rotterdam Ophthalmic Institute, P.O. Box 70030, 3000 LM Rotterdam, Netherlands
3. Rotterdam Eye Hospital, P.O. Box 70030, 3000 LM Rotterdam, Netherlands
4. Department of Biostatistics, Erasmus MC, P.O. Box 2040, 3000 CA Rotterdam, Netherlands
5. Royal Dutch Visio, P.O. Box 1180, 1270 BD Huizen, Netherlands