Question: what is the normal vision of human eye
[{'answer': '20 / 20'}, {'provenance': [{'wikipedia_id': '648954', 'title': 'Visual acuity', 'start_paragraph_id': 7, 'start_character': 0, 'end_paragraph_id': 7, 'end_character': 417, 'bleu_score': 0.709000347904134, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16890198914164789904}, 'section': 'Section::::Definition.\n'}]}]