US 6,788,421 B2 · Arrangements for coherence topographic ray tracing on the eye

Abstract

Topographic measurement of eye structures based on short coherence interferometry is the subject of the invention. The problem occurring in this connection is that longitudinal and transverse eye movements during signal registration lead to errors in the measured structure. The influences of longitudinal eye movements are compensated in that the reference beam, independent from the measurement beam, is directed to the corneal vertex and is reflected at the latter. The influences of longitudinal eye movements are minimized in that the transverse position of the eye is monitored by means of a direction-dependent registration of the light reflected at the corneal vertex by means of a diode array or a four-quadrant diode and transverse misalignment is detected and compensated.

Claims5

Dependent claims

An arrangement for coherence topography of the eye by a series of depth signals which are measured by short coherence interferometry in different pupil points by scanning an optical length of a reference arm of a two-beam interferometer, comprising that:

a first device that radiates a measurement beam of a short coherence interferometer into the pupil of an eye in a series of measurement positions;
and
a second device that fixedly directs a reference beam, independent from the measurement beam, to the corneal vertex, the reference beam being reflected at the corneal vertex.

Dependencies are inferred from the claim text.

Arrangements for coherence topographic ray tracing on the eye

Life of this patent

Arrangements for coherence topographic ray tracing on the eye

Life of this patent

Abstract

Claims5