At what eye degree can you still watch tv comfortably without needing glasses or contacts?

Depends. Some people are ok with 20/40 vision, other people can' t stand to not have crystal clear vision. If you are squinting to see the tv or if it is not comfortable for you to watch tv than glasses would definitely help!
Depends. If you are having no problems now don' t worry. This is subjective . Some people do just fine with 20/40 vision, other people need to see better. If you are squinting to see the tv then you will need glasses.