Method and an apparatus for determining the refraction
OwnerHelmut Kruegerinventor
Life of this patent
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Abstract
The invention relates to a method for determining the refraction of the human eye. The retinal image of an object is imaged via a lens system into an object space and into an image plane which is conjugated with respect to the retina. The spacing of the conjugated plane is analyzed to determine the refraction of the human eye. This analysis is carried out by means of a measuring object which is moved along a plane which is defined by rays of the beam of rays which pass through image points of the retinal image of a target object, such that the beam of rays is divided into two complementing partial beams containing an unevenly divided amount of light energy. The unevenly divided light energy is used to determine the distance of said conjugated plane.
Claims23
A method for determining the time dependent refraction of the human eye comprising the steps of:
- (a) imaging a target object having an extension in depth in the direction of the optical axis in an object space onto the retina of the eye with an optometer lense system such that the retinal image of said object is re-imaged via said lense system into the object space and into an image plane which is conjugated with respect to the retina and depends on the refraction of the eye and the index of refraction of the lense system, the distance of said conjugated image plane from said lense system being a measure of refraction,
- (b) separating the beam of rays from the target object from the beam of rays from the retinal image by means of said target object comprising at least two parial portions, said partial portions being edges of the target object and extending parallel to each other, and
- (c) simultaneously analyzing the beam of rays from the retinal image at at least two different distances from the conjugated image plane by means of said target object.
A method for determining the time-dependent refraction of the human eye comprising the steps of:
- (a) imaging a target object in an object space onto the retina of an eye with an optometer lense system such that the retinal image of said object is re-imaged via said lense system into the object space and into an image plane which is conjugated with respect to the retina and depends on the refraction of the eye and the index of refraction of the lense system, the distance of said conjugated image plane from said lense system being a measure of refraction,
- (b) separating the beam of rays from the target object from the beam of rays from the retinal image, and
- (c) analyzing the beam of rays from the retinal image so as to determine said distance of the conjugated plane by means of a measuring object wherein said measuring object is guided along at least one plane through said beam of rays from said retinal image, said plane being defined by rays of the beam of rays which pass through image points of the retinal image of the target object, and divides the beam of rays into two complementing partial beams such that the light energy of the beam of rays is unevenly divided between said two complementing partial beams, causing unevenly divided light energy in said partial beams, said unevenly divided light energy being used to determine said distance of said conjugated plane.
Dependencies are inferred from the claim text.