You can visit them, especially when they are sick or confined. Moreover, you can and should always treat them as mature adults.
كَمَا يُمْكِنُكَ أَنْ تَزُورَهُمْ ،‏ وَخُصُوصًا حِينَ يَكُونُونَ مَرْضَى أَوْ طَرِيحِي ٱلْفِرَاشِ .‏