Rimless eyeglasses, are a type of eyeglasses in which the lenses are mounted directly to the bridge and/or temples by way of a series of screws or hollow plastic double rivets that fit into two holes in the lens, rather than the lenses being secured inside of frames which encircle the lens. When plastic rivets are used the temples and bridge have barbed metal pins that lock into the hollow rivets. The plastic rivet method has the advantages of being cheap, no threads to strip or loosen, and can be replaced by a handy owner. The style is divided into two subtypes: three piece glasses are composed of lenses mounted to a bridge and two separate temple arms, while rimways (also called cortlands) feature a supporting arch that connects the temples to the bridge and provides extra stability for the lenses. Rimless glasses were a popular style of eyeglasses from the 1880s until into the 1960s, and re-emerged in popularity in the latter part of the 20th century and early 21st century.