The human iris is a thin circular structure in the eyes which is responsible for controlling the diameter and size of the pupils. It also controls the amount of light which is allowed through to retinal in order to protect the eye's retina. Iris color is also a variable different to each person depending upon their genes. Iris color will decide eye color for each individual. There are several colors for iris such as: brown (most popular color for the iris), green, blue, grey, hazel (the combination of brown, green and gold), violet, pink (in really rare cases). The iris also has its own patterns from eye to eye and person to person, this will make up to uniqueness for each individual.

Iris recognition systems will scan the iris in different ways. It will analyze over 200 points of the iris including: rings, furrows, freckles, the corona and others characteristics. After recording data from each individual, it will save the information in a database for future use in comparing it every time a user want to access to the system.

Iris recognition security systems are considered as one of the most accurate security system nowadays. It is unique and easy to identify a user. Even though the system requires installation equipment and expensive fees, it is still the easiest and fastest method to identify a user. There should be no physical contact between the user and the system during the verification process. During the verification process, if the users are wearing accessories such as glasses and contact lenses, the system will work as normal because it does not change any characteristics of the user's iris. Theoretically, even if users have eye surgery, it will have no effect on the iris characteristics of that individual.