Ophthalmic apparatus and method of alignment of ophthalmic apparatus

Abstract

An ophthalmic apparatus comprises an illumination channel for illuminating a retina of an eye in response to a distance between the ophthalmic apparatus and the eye being within a working range of the ophthalmic apparatus. An imaging channel collects light reflected from the retina. An image capturing arrangement captures images of the retina through the imaging channel while the distance between the ophthalmic apparatus and the eye is within a working range of the ophthalmic apparatus. A chromatic arrangement causes and/or imitates a longitudinal chromatic aberration of light directed toward an eye while a longitudinal aberration range is at least partially overlapping with a frontal section of an eye between an outer surface of a cornea and a rear surface of a crystalline lens in response to a distance between the ophthalmic apparatus and the eye being within a working range. A collection optics collects light reflected from the frontal section of the eye. An optical spectrum analyzer outputs signals, a single signal of the signals carrying information on intensity of a single wavelength band of the different wavelength bands. A data processing unit measures intensities carried by the signals and determines a distance and/or a need for adjustment of the distance between the ophthalmic apparatus and the eye based on peak(s) of the signals, the peaks being caused by reflections from at least one surface of the eye.