An "iris scanner" is a technology that uses a person's unique pattern in their eye called the iris to identify them. It is like a special camera that takes a picture of your eye to make sure it is really you. Full definition
It was also revealed that the device would ship with an advanced iris scanner on board for enhanced security and payment authorization. (techtimes.com)
At the top of of the phone we can see an array of sensors, which are believed to include a much - improved iris scanner and the front - facing camera. (pocket-lint.com)
The handset is also expected to feature an advanced iris scanner, which will be among its most notable features. (techtimes.com)