The Secure Identity Preservation system uses a biometric marker called the retinal vascular pattern - the pattern of blood vessels located at the back of the eye. The retinal vascular pattern is present from birth, unchanging from birth to death and unique to each animal.
The reflective layer present at the back of the eye provides a contrast to the vessels and facilitates a clear, easy-to-read retinal image. Although each species (i.e., cattle, sheep, pigs) shares the same basic pattern, individual variation is sufficient to allow, with essentially 100% accuracy, the capture and identification of an individual animal's image.
The landmarks used in the identification process are the patterns created by the retinal blood vessels. These are highly unique, not only between animals, but also between eyes within the same animal. The image at the right demonstrates clearly the presence of the same basic pattern in cows, with significant individual differences that allow for identification.
Because each eye of the same animal is different, the identification system is even more robust. If one eye is lost, the other provides a back up method of identification. The image is obtained through the pupil so there is only one direction from which to view it, ensuring that the same view will always be obtained.
