Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2004 Jan 28:3:2.
doi: 10.1186/1475-925X-3-2.

Iris recognition as a biometric method after cataract surgery

Roberto Roizenblatt  1 , Paulo Schor, Fabio Dante, Jaime Roizenblatt, Rubens Belfort Jr
Affiliations

Iris recognition as a biometric method after cataract surgery

Roberto Roizenblatt et al. Biomed Eng Online. .

Abstract

Background: Biometric methods are security technologies, which use human characteristics for personal identification. Iris recognition systems use iris textures as unique identifiers. This paper presents an analysis of the verification of iris identities after intra-ocular procedures, when individuals were enrolled before the surgery.

Methods: Fifty-five eyes from fifty-five patients had their irises enrolled before a cataract surgery was performed. They had their irises verified three times before and three times after the procedure, and the Hamming (mathematical) distance of each identification trial was determined, in a controlled ideal biometric environment. The mathematical difference between the iris code before and after the surgery was also compared to a subjective evaluation of the iris anatomy alteration by an experienced surgeon.

Results: A correlation between visible subjective iris texture alteration and mathematical difference was verified. We found only six cases in which the eye was no more recognizable, but these eyes were later reenrolled. The main anatomical changes that were found in the new impostor eyes are described.

Conclusions: Cataract surgeries change iris textures in such a way that iris recognition systems, which perform mathematical comparisons of textural biometric features, are able to detect these changes and sometimes even discard a pre-enrolled iris considering it an impostor. In our study, re-enrollment proved to be a feasible procedure.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Iris code from an iris-scan. (Adapted from [3] (© 1990 IEEE))
Figure 2
Figure 2
General formalism for biometric decision making (Adapted from [6] (© 1999 IEEE))
Figure 3
Figure 3
Decision environment for iris recognition under ideal laboratory conditions (Adapted from [5] (© 1993 IEEE))
Figure 4
Figure 4
Color and infrared photos of a patient before and after the cataract surgery Same iris, before and after surgery. (A and B) Color photos. (C and D) Infrared photos of subject A and B (E and F) Barely visible changes. Score 0. (G and H) Light depigmentation. Score 1.
See this image and copyright information in PMC

References

    1. Nanavati S, Thieme M, Nanavati R. "Biometrics: identity verification in a networked world.". New York: John Wiley & Sons, Inc; 2002.
    1. Daugman J. Institute of mathematics and its applications. Cambridge: Horwood; 2000. Wavelet demodulation codes, statistical independence, and pattern recognition; pp. 244–60.
    1. Daugman J. How iris recognition works. The Computer Laboratory, University of Cambridge. [Acessed 2003 Jan 23 at http://www.CL.cam.ac.uk/users/jgd1000]
    1. Ronald AllenL, Duncan MillsW. "Signal analysis: time, frequency, scale, and structure.". New York: IEEE Press, John Wiley & Sons Inc; 2004. pp. 338–351.
    1. Daugman JG. High confidence visual recognition of persons by a test of statistical significance. IEEE Trans Pattern Anal Machine Intell. 1993:1148–61. doi: 10.1109/34.244676. - DOI

Publication types

LinkOut - more resources