Updated August 2026 Anyone who rides a train, works in an open office, or answers email in a waiting room has felt it: the person next to you reading your screen. Sometimes it is idle curiosity. Sometimes, if you handle client data, medical records, or banking on your phone, it is a genuine security problem with a name, shoulder surfing. Privacy screen protectors exist for exactly this. They make your screen readable to you and dark to anyone looking from the side. The technology is clever, it works, and it comes with tradeoffs you should understand before buying one. Here...