The word Chamomile comes from the Greek meaning ground apple, probably because of its apple-like fragrance. The Romans used Chamomile for incense. Roman Chamomile gained its name, not from ancient Rome, but because a 19th century plant collector found some growing on the ruins of the coliseum in Rome.
What Is Perfect Vision? In cases of normal vision, also called perfect vision or 20/20 vision, the eye is able to focus light from objects precisely on the retina at the back of the eye. Refractive errors occur when the eye is unable to properly focus light on the retina.
Maximum Aperture (Minimum f-number). The maximum diameter of the lens opening is referred to as its maximum aperture or minimum f-number. The minimum f-number is the smallest f-number that can be selected with the lens.