Authentication using biometrics has been associated generally with costly top secure applications. Iris recognition is fast emerging highly secure biometric. Efficiency of recognition stage highly depends on Iris detection and localization. In this paper, the authors evaluate different iris localization and detection techniques: Daugman's Integro-Differential operator and direct least square fitting of ellipse. CASIA-Iris-Interval-v3 database is used for evaluation. Iris's inner and outer boundaries where found using Daugman's Integro-Differential Operator in first case. Iris's inner boundary was found using direct least square fitting of ellipse in second case. Improper illumination, eye lashes and spotlight effects are major occlusions.