Method for determining the refractive power of a transparent object, and corresponding device

A method for determining a refractive power of a large-surface-area transparent object, the method comprising the steps of:

• capturing a first imaging of a first line grating through the transparent object using a camera at at least one predetermined point of the transparent object;
• using the central processing unit to determine a line spacing of the first imaging transverse to lines of the first line grating at the at least one predetermined point;
• capturing a second imaging of a second line grating and a third imaging of a third line grating through the object using the camera, wherein lines of the second line grating extend at an angle not equal to 0° with respect to the lines of the first line grating and lines of the third line grating extend at an angle not equal to 0° with respect to the lines of the first line grating and extend at an angle not equal to 0° with respect to the lines of the second line grating;
• using the central processing unit to determine respective line spacings of the second imaging and the third imaging transversely to the respective lines of the second line grating and third line grating, based on the second imaging and the third imaging and a rotation of the lines relative to the respective second line grating and third line grating;
• and
• using the central processing unit to calculate the refractive power in every azimuthal direction at the at least one predetermined point of the transparent object based on the determined line spacings and the rotation of the lines relative to the respective first line grating, second line grating and third line grating.

A device for determining a refractive power of a large-surface-area transparent object, comprising:

• a camera;
• a central processing unit;
• a first line grating defined by first grating lines;
• a second line grating defined by second grating lines, which second grating lines extend at an angle not equal to 0° with respect to the lines of the first line grating;
• and
• a third line grating defined by third grating lines, which third grating lines extend at an angle not equal to 0° with respect to the lines of the first line grating and with respect to the lines of the second line grating;
• wherein the camera captures a first imaging of the first line grating through the transparent object at at least one predetermined point of the object,
• wherein the central processing unit processes the first imaging to determine a line spacing of the first imaging transversely to the first grating lines at the particular point;
• wherein the camera captures a second imaging of the second line grating and a third imaging of the third line grating through the transparent object;
• and
• based on the second imaging and the third imaging, the central processing unit determines a line spacing of the second imaging transversely to the second grating lines and a line spacing of the third imaging transversely to the third grating lines;
• and
• based on the determined line spacings and with consideration for the rotation of the lines relative to the respective line grating, the central processing unit determines the refractive power in every azimuthal direction at the at least one predetermined point of the transparent object.