FTN â **** the Navy. Commonly used as graffiti in hard to find places as a type of game. While there are no clear objectives, the result of upsetting officers constitutes a type of victory.
Bifocals, are eyeglasses with two distinct optical powers, Bifocals are commonly prescribed to people with presbyopia who also require a correction for myopia, hyperopia, and/or astigmatism.
Trifocal lined lens vs. Progressive lens. Trifocals have three diopters with sudden passing between them while progressive lens has all the intermediate diopters from the distance to near and for the eye is more easily to accommodate with the different distances.