purpose : to determine cyclotorsional eye movement between the upright position and the supine position, in iranian patients with high preoperative astigmatism methods : this prospective cross sectional study contains 102 eyes of 59 patients who were candidates for refractive surgery with technolas 217z100 excimer laser system for correction of high astigmatism. wavefront measurements using zyw...

PURPOSE To evaluate the residual registration error after limbal-marking-based manual adjustment in cyclotorsional tracker-controlled laser refractive surgery. METHODS Two hundred eyes undergoing custom surface ablation with the iVIS Suite (iVIS Technologies) were divided into limbal marked (marked) and non-limbal marked (unmarked) groups. Iris registration information was acquired preoperati...

Biometric technologies are the foundation of personal identification systems. It provides an identification based on a unique feature possessed by the individual. This paper provides a walkthrough for image acquisition, segmentation, normalization, feature extraction and matching based on the Human Iris imaging. A Canny Edge Detection scheme and a Circular Hough Transform, is used to detect the...

This paper studies the iris recognition problem in the degraded iris images captured in non-ideal imaging conditions. In these circumstances iris recognition becomes challenging because of noisy factors such as the off-axis imaging, pose variation, image blurring, illumination change, occlusion, specular highlights and noise. We introduce a robust algorithm based on the Random Sample Consensus ...

Biometric technology deals with recognizing the uniqueness of individuals based on their exclusive Physical or behavioral characteristics. The developments in science and technology have made it possible to use biometrics in application when it is required to establish (or) confirm the identity of persons. Amongst a range of method, Iris recognition is a hastily intensifying technique of biomet...

This paper presents an efficient algorithm for iris recognition using phase-based image matching. The use of phase components in twodimensional discrete Fourier transforms of iris images makes possible to achieve highly robust iris recognition with a simple matching algorithm. Experimental evaluation using the CASIA iris image database (ver. 1.0 and ver. 2.0) clearly demonstrates an efficient p...

Information security is concerned with the assurance of confidentiality, integrity and availability of information in all forms. It provides an identification based on a unique feature or characteristic possessed by the individual. Among various techniques, Iris recognition is a rapidly expanding method of biometric technology. A wide variety of recognition schemes is used to either confirm or ...

The use of wavefront-guided algorithms for treatment has increased over the past decade with estimates that up to 50 percent of all laser in situ keratomileusis (LASIK) procedures are now performed with this approach1. Although originally intended to correct higher order aberrations, the use of wavefront-guided algorithms, particularly those with iris-registration and tracking, have been shown ...

Ocular biometrics has made significant strides over the past decade primarily due to the rapid advances in iris recognition. Recent literature has investigated the possibility of using conjunctival vasculature as an added ocular biometric. These patterns, observed on the sclera of the human eye, are especially significant when the iris is off-angle with respect to the acquisition device resulti...