It can effect lung development
Answer:
You should consider if the fully cover your eyes, thickness, clearness, if they fog easily or not, grip so they won't slip off.
Weaker bones
higher risk of some illnesses
having less cortisone
needing less sleep
"Let's try that posture again so we can see how you can avoid hurting your neck." This is the best answer, because this is this the nicest way for Randall to inform his friend of his bad posture without discouraging the friend.