Multi-camera system for describing the tear film of an eye

An ophthalmic system for describing a tear film of an eye, the ophthalmic system comprising:

• a pattern illuminator configured to direct a pattern of light towards an anterior surface of the eye, the anterior surface having a plurality of surface points, the anterior surface reflecting the pattern of light as a reflected pattern;
• at least a first camera and a second camera, the first and the second cameras configured to generate respective first and second images of the reflected pattern, the second camera comprising an off-axis camera, the first image including a plurality of first image points corresponding to one or more surface points of the plurality of surface points of the anterior surface and the second image including a plurality of second image points corresponding to the one or more surface points of the plurality of surface points of the anterior surface;
• and
• a computer configured to:
• perform the following for at least two iterations to yield a plurality of descriptor sets of the tear film generated during a sequence of times:
• receive the first and the second images of the reflected pattern from the first and the second cameras generated at a given time of the sequence of times;
• for the first image at the given time, determine a plurality of first tear film values for the first image points to yield a first plurality of tear film values for the plurality of surface points;
• for the second image at the given time, determine a plurality of second tear film values for the second image points to yield a second plurality of tear film values for the plurality of surface points;
• for each surface point of the plurality of surface points, determine a tear film descriptor of the tear film at the each surface point from at least the first tear film value and the second tear film value for the each surface point, to yield a plurality of tear film descriptors for the plurality of surface points;
• and
• generate a descriptor set that describes the tear film from the plurality of tear film descriptors of the plurality of the surface points of the anterior surface at the given time;
• and
• generate a tear film description according to the plurality of descriptor sets generated during the sequence of times.