Tablets that measure pupil dilation to determine whether you’re in the mood to watch a horror movie or a comedy.
Headbands, socks and bras that analyze brain waves, heart rates and sweat levels to help detect early signs of disease or gauge a wearer’s level of concentration.
Cars that recognize their owner’s voice to start engines and direct turns and stops, all hands-free.
This week in Las Vegas at the annual International Consumer Electronics Show, or CES, personal technology will get much more personal, with the proliferation of biometric tools to create more-customized online experiences while also testing new boundaries on privacy.