GI glasses

GI glasses are eyeglasses issued by the American military to its service members. Dysphemisms for them include the most common "birth control glasses" (also called "BCGs") and other variants. At one time, they were officially designated as regulation prescription glasses, or RPGs. This was commonly said to mean "rut prevention glasses" due to their unstylish appearance.

History

The original version was designed for use with gas masks during World War II. It was wire-rimmed with cable temples and a "P3" lens shape. The design was a modification of the "panto" shape used by the British military.

After WWII, the material was switched from nickel alloy wire to cellulose acetate. Initially gray cellulose acetate was used, but this was discontinued in 1968, with remaining stocks issued until exhausted. The replacement frames used black cellulose acetate.

In the late 1970s, the lens shape was re-designed to the "S9". Black "S9" frames were released for a brief period, before brown cellulose acetate replaced the black. The brown cellulose acetate frames were discontinued in 2012, and a new smaller unisex lens shape, the "5A", was introduced, with a black frame. The modern "5A" shape was designed by Rochester Optical, who is the exclusive manufacturer of the R-5A frame.