Iris recognition technology involves the use of a camera to capture an image of the iris, the colored portion of the eye. The iris is an excellent choice for identification: it is stable throughout one's life, it is not very susceptible to wear and injury, and it contains a pattern unique to the individual. Indeed, an individual's right and left iris patterns are completely different.
There are two types of iris recognition systems: active and passive. In the active system, the user must adjust the camera by moving forward or backward a few inches in order to bring the iris into focus. Further the user must be within 6 - 12 inches of the camera. This requires substantial supervision and instruction. The passive system incorporates a set of cameras to automatically locate the users face and eye, therefore removing the need to manually focus the camera. This system is substantially easier to use.
There are two key public acceptance issues: intrusiveness and ease of use. While the passive system is not physically intrusive, there are some people who are hesitant to use the system due to the fact that the camera is taking a picture of one's eye.
Active iris scan requires more participation on the part of the user because the system needs to be manually focused and the user must be close to the camera. The user sees a picture of his eye image and is more aware of what the that the system is doing. Although the technology is very similar to passive iris scan, the process is less transparent and thus seen as more intrusive.
Iris scan is the most expensive biometric technology costing tens of thousands of dollars. This technology has only been commercially available for a few years and is not being mass-produced.
The active iris scan system, which must be manually focused, costs several thousand dollars. This price includes the camera hardware and the PC loaded with the software necessary to run the application.