Method for determining distances in the anterior ocular segment

US7284858B2 · kind B2 · utility

Assignee

• Carl Zeiss Meditec AG · DE

Inventors

• Roland Bergner · Jena, DE
• Roland Barth · Schreiber, CA
• Axel Doering · Jena, DE
• Frank Behrend · Jena, DE
• Klaus-Ditmar Voigt · Jena, DE

Key dates

• Filing date: Feb 16, 2002
• Grant date: Oct 23, 2007
• Expiry date: Nov 8, 2023

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61B3/112
• WIPO field: Medical technology
• WIPO sector: Instruments

Abstract

The invention relates to a method for determining distances in the anterior ocular segment, preferably of the pupils and/or the diameter of the iris, wherein the image of at least part of the eye is recorded and digitized using an imaging device and an array for illuminating the eye. On the basis of said digital image, a center of gravity analysis and the determination of the central point are carried out, especially for the position of the pupils, by conducting an intensity and threshold analysis as rough determination. Based on said rough determination, a fine detection of the position of the edges of the pupil and/or the edges of the iris is carried out. Additionally, the angle between the visual axis and the optical axis of the eye can be determined from the position of a fixed reflection to the center of the pupil and/or the center of the iris.