The original Ray-Ban Aviator’s commonly cited lens size is 58 mm.
In eyewear sizing, 58 mm refers to the horizontal width of one lens, not the total width of the sunglasses. It is typically paired with a 14 mm bridge measurement, written as 58–14. The classic Aviator is also sold in other sizes, so the number identifies the standard original-style size rather than every Aviator ever produced.
Ray-Ban’s Aviator design began with aviation eyewear developed by Bausch & Lomb. The large lenses were intended to cover much of a pilot’s field of vision and reduce glare while flying. The teardrop outline also accommodated pilots who needed to look down toward instrument panels without leaving the lower eye exposed.
A common mistake is treating 62 mm as the original size simply because it is the larger option in some product ranges. Ray-Ban’s Aviator families have included 55 mm, 58 mm and 62 mm versions, depending on the model and fit. For a general trivia question about the original classic Aviator, however, 58 mm is the standard answer.