PROBLEM TO BE SOLVED: To provide a visual function regenerating agent having a visual function regenerating ability or a visual function lowering preventive agent. SOLUTION: The visual function regenerating agent or the visual function deterioration containing a chimeric protein having an amino acid sequence of a microorganism-derived ion transport type receptor rhodopsin and an amino acid sequence of an animal-derived G protein-coupled receptor rhodopsin as an active ingredient. Preventive agent. [Selection diagram] Figure 2【課題】視覚機能の再生能を有する視覚機能再生剤又は視覚機能低下予防剤の提供。【解決手段】微生物由来のイオン輸送型受容体ロドプシンのアミノ酸配列と動物由来のＧタンパク質共役型受容体ロドプシンのアミノ酸配列とを有するキメラタンパク質を有効成分として含有する、視覚機能再生剤又は視覚機能低下予防剤。【選択図】図２
