Get your starter. The starter's job is to provide acetic acid bacteria, which converts ethanol into acetic acid (the primary ingredient in vinegar). Unpasteurized, unfiltered vinegar. It's important to use vinegar that hasn't been processed in a way that interferes with the acetic acid bacteria. Mother of vinegar.
Pupillary distance. Pupillary distance (PD) or interpupillary distance (IPD) is the distance (the industry standard is to measure in millimeters) between the centers of the pupils in each eye. This measurement is used when preparing to make prescription eyeglasses.
Some additional details for PD measurement: +++++ Pupillary Distance Measurement Pupillary Distance is the distance between the center of one pupil (the central black dot of your eye) to the center of the other pupil. Measured in millimeters, PD is important as it helps the laboratory technician to accurately create your eyeglasses frames by lining up your pupil with the center of the lens. As for obtaining your PD