Calculating conjunctival redness

A system for evaluating a condition of an ocular surface, the system comprising:

• an imaging system configured to obtain one or more digital images of the ocular surface;
• and
• a controller in communication with the imaging system, the controller configured to execute instructions to perform operations comprising:
• determining, from a plurality of Cartesian space-based color components represented in a portion of the one or more digital images, a value of a first component in a polar coordinate-based color space, the polar coordinate-based color space consisting of first, second, and third components;
• determining, in response to the first component being within a range in the polar coordinate-based color space representing a color range associated with the condition, a color value as a function of the value of the first component of the polar coordinate-based color space and at least one of the first component or the second component of the polar coordinate-based color space, the function being based on the condition being evaluated;
• and
• generating, based on the color value, a color score of the ocular surface representing a quantitative evaluation of the condition of the ocular surface.