How to acommodate elderly wedding guests?

Me (24 F) and my fiance (24 m) are getting married this autumn and we are lucky enough to have most of our grandparents able to attend. Do you have any tips how to help them to have pleasant experience? They are quite healthy, but they are in their 80s, so they have mild issues with mobility, hearing etc. I cant ask them personally because they will say no worries with me. But I want to have them in mind during planning proces.