instructions. If in doubt, please ask your optician for help. Can I charge the battery handle of the VarioPlus system and use it at the same time? No. For technical reasons, it cannot be used during the 4-hour [...] When the eye compensates through accommodation, this often leads to eye strain, fatigue and headache. Plus powered lenses, which bundle the incoming light, can be used to correct long sightedness. What is [...] sufficient for a person to be able to orientate themselves outdoors. However, a visual acuity of 0.8 is required for reading travel timetables. Other minimum values include: 0.4 for watching television