Measurements using a single image capture device

An apparatus comprised of:

• an image capture device;
• a memory;
• and
• a processor in communication with the memory and the image capture device, wherein the processor executes computer-readable instructions stored in the memory that cause the processor to;
• capture, using the image capture device, a first image comprising an eye, wherein the first image of the eye comprises an iris of the eye;
• determine a number of pixels in the first image that span a diameter of the iris of the eye;
• divide the determined number of pixels that span the diameter of the iris of the eye by an estimated iris diameter to determine a ratio of pixels per unit of measure for the first image;
• and
• determine, based upon the determined ratio of pixels per unit of measure for the first image, a size or shape of any object in the captured first image or a first distance between any two objects or points in the captured first image.