My cat was an indoor and outdoor cat, came and went as she pleased. Towards the end of her life she went virtually blind but still liked to walk down the garden to sniff things out. I can't imagine her having a full life by being kept indoors, they naturally like to climb trees and jump. Allowing the freedom to exercise freely also keeps their weight down. Overweight cats can have a shorter life because of health issues caused by obesity. She passed away in January but had a very happy 20 years of being with us :O)