Every smartphone these days comes equipped with a WiFi card. When the card is on and looking for networks to join, it’s detectable by local routers. In your home, the router connects to your device, and then voila — you have the Internet on your phone.
Messages and images would simply appear in front of your eyes, generated by a computerised contact lens. Of course, you may not always want to be bothered by such messages if you are doing anything so quaint as – for instance – reading a book or going out walking and enjoying the scenery.