Abstract: A device for performing distance measurements on an eye. The device includes an interferometer, focuses at least one measurement beam records backscattered radiation and interferometrically generates a measurement signal displaying structures of the eye by time-domain, spectral-domain or Fourier-domain coherence reflectometry, has an adjustment apparatus for laterally and/or axially displacing the focus in the eye or for varying a polarization state of the measurement beam and has a control apparatus which actuates the interferometer, wherein the control apparatus generates a plurality of A-scan individual signals from the backscattered radiation, combines these to an A-scan measurement signal and actuates the adjustment apparatus for displacing the position of the focus or for varying the polarization while recording the backscattered radiation from which the control apparatus generates the A-scan individual signals is being recorded.

Abstract: An optical time domain coherence tomograph including an object beam path, a detection beam path and a detector unit. An interferometer unit, which has a first and a second beam path part having different optical path lengths, splits radiation and feeds it into the two beam path parts and superimposes it again after passage through the beam path parts and thus generates a dual beam, which has components which are axially offset to one another because of the differing optical path lengths of the two beam path parts. A scanning unit has a first adjuster and a second adjuster for adjusting the optical path length of the first and second beam path parts and the first and the second adjustment means adjusting the path length for scanning the object in coordination to one another under control by the control unit.

Abstract: For the pre-operative calculation of the power of an intraocular lens, three input parameters are needed: the axial length of the eye (AL), the refractive power of the cornea, and the distance between the front of the cornea and the back focal plane of the intraocular lens, the so-called effective lens position (ELP). The invention shows a novel approach to the determination of the ELP.