Stubborn or what?

Oh my goodness! I’m tired of telling my son to not to stay close to the TV because it’s not good for him. I don’t want him to have eye problem at the very young age; as much as I can I will have to take the precautions than letting him do what he wants. I don’t think he’s ignoring me because he doest really understand why, because he’s just 3 years old. I just have to say the same words repetitively so he’ll remember otherwise the TV will be turn-off.