American Optical Company

Founded in 1833 by William Beecher, AO was later bought by fellow apprentice Robert H. Cole who became the largest shareholder and first president of the company.

[4] After a visit by John F. Kennedy in 1958 to its original manufacturing site in Southbridge, Massachusetts, AO became a go-to brand of the president.

In 1982, it sold the vision care and industrial safety business, while retaining its ophthalmic instruments and fiber optic products.

The D-1 flying goggle assembly was standardized on 13 August 1935, and was actually a pair of sun glasses with a rigid frame and plastic insulated arms.

[13] Despite being designed for utility, these glasses had advanced properties: teardrop-shaped convex lenses, plastic nose pads, a prominent brow bar and flexible cable temples.

[13] In 1958 American Optical created the Flight Goggle 58 according to the then new U.S. Air Force Type HGU-4/P aviator sunglasses standard.

The HGU-4/P design frame allowed the visor to reliably clear the aviator's spectacles when a flight helmet is worn, and covers the full field of vision.

The frame additionally features bayonet temples designed to slip under a flight helmet or other headgear and were more compatible with oxygen masks.

One of the many specifications is that the neutral grey lenses used in Type HGU-4/P aviator sunglasses must transmit between 12% and 18% of incoming visible daylight whilst providing 'true' color and contrast distribution.