Planning the yard to be care recipient friendly

I have been working on what I will be doing out in the yard to get it ready for summer and one of the biggest challenges is designing it to be accessible for my dad. I want to be sure that he can enjoy the yard as much as the rest of us, but there are problems such as mosquitoes and sunlight - one of the medications he is taking makes him sunburn easily.

So, I'm pondering things and trying to figure around the areas where the best shade is. Seems like one of the most challenging yard plans I have tried to come up with.